Secretary of State Antony J. Blinken and his Russian counterpart on Thursday held the primary non-public, face-to-face change between a U.S. cupboard member and a high Kremlin official because the invasion, and Mr. Blinken mentioned he used the encounter to demand that Russia finish its battle on Ukraine.

The unscheduled encounter with Sergey V. Lavrov, Russia’s overseas minister, at a global convention in New Delhi confirmed that the Biden administration noticed a must reestablish in-person diplomatic contacts with Moscow so the 2 governments can talk about the year-old battle in addition to points past it.

Mr. Blinken mentioned at a information convention on Thursday evening that along with calling for Russia to halt its “battle of aggression” in Ukraine, he instructed Mr. Lavrov that Russia ought to return to the New START nuclear arms management treaty it withdrew from final month and adjust to its phrases. And he as soon as once more urged Moscow to free Paul Whelan, an American citizen who the State Division says is wrongfully imprisoned on espionage costs.

The assembly with Mr. Lavrov, which lasted lower than 10 minutes, occurred on the sidelines of a gathering right here of high diplomats from the Group of 20 nations representing the world’s largest economies. Within the morning, Mr. Blinken mentioned in a bunch session that was additionally attended by Mr. Lavrov and Qin Gang, the overseas minister of China, that the international locations needed to proceed to name on Russia to “withdraw from Ukraine for the sake of worldwide peace and financial stability.”

The encounter got here at a essential second within the largest and most harmful battle in Europe since World Warfare II. Each side are marshaling extra troops and weapons for deliberate spring offensives, hoping to attain decisive breakthroughs. Russian troops are closing in on the besieged metropolis of Bakhmut, Ukraine, amid heavy casualties, however there was little latest motion on the battlefield.

On the Group of 20 assembly, Russia and China, its strongest companion, blocked the overseas ministers from issuing a consensus communiqué on the finish of the convention, arguing towards strains that criticized Russia’s actions in Ukraine.

As a substitute, the group launched a considerably lower-level assertion that mirrored the truth that 18 of the 20 nations condemned the invasion, exhibiting that even some international locations with an formally impartial stance — India, Indonesia, South Africa and Saudi Arabia amongst them — had been prepared to tilt towards Russia in some settings. At a gathering in Bali in November, President Biden and different Group of 20 leaders agreed to a doc with the identical essential language.

Russian officers mentioned Mr. Blinken had sought out the assembly with Mr. Lavrov, though Mr. Blinken instructed reporters a day earlier, earlier than he flew from Uzbekistan to India, that he had no plans to fulfill on the convention with Mr. Lavrov or Mr. Qin. Mr. Blinken didn’t meet along with his Chinese language counterpart on Thursday.

The assembly between Mr. Lavrov and Mr. Blinken doesn’t sign any motion towards beginning talks on ending the battle in Ukraine. Maria Zakharova, a Russian Overseas Ministry spokeswoman, mentioned that “there have been no negotiations” between the 2 males, in keeping with Interfax, a Russian state information company.

On Wednesday, Mr. Blinken mentioned at a information convention in Tashkent, the Uzbek capital, that the Biden administration noticed “zero proof” that President Vladimir V. Putin of Russia was critical about starting substantial negotiations.

In actuality, he mentioned on Thursday, Mr. Putin is “doubling down on his brutalization of Ukraine.” Mr. Blinken reiterated that Mr. Putin was the one one who may meet the situations for peace — by absolutely withdrawing from Ukraine.

President Biden and his aides say their purpose for now’s to maintain giving Ukraine army support to repel Russia and take again Ukrainian territory, and that any peace talks, an concept that China and some different nations are pushing, are a distraction to assist Mr. Putin attempt to solidify his positive factors and proceed his assaults in Ukraine. Mr. Blinken instructed Mr. Lavrov that the US was dedicated to defending Ukraine “for so long as it takes,” a senior State Division official mentioned.

There was no indication that Mr. Lavrov addressed Mr. Blinken’s calls for. However at a United Nations Convention on Disarmament in Geneva, a Russian official repeated Moscow’s causes for suspending participation within the New START treaty. The Russian envoy, Sergey Ryabkov, accused the US and its European allies of making an attempt to “strategically defeat” Russia and of aiding Ukraine with the intention to assault Russian strategic websites recognized underneath the treaty.

Mr. Blinken introduced up the battle in different non-public conferences throughout the convention. When he spoke with Subrahmanyam Jaishankar, the Indian overseas minister, the 2 “mentioned how you can mitigate the worldwide impacts of Russia’s unlawful battle in Ukraine” and “the US and India’s cooperation within the Indo-Pacific,” the State Division mentioned in an announcement. The second phrase is a reference to strategic efforts in Asia, together with army coordination, to counter China.

However Prime Minister Narendra Modi of India, who has been pleased with his skill to convey the sequence of Group of 20 conferences to his nation this yr, expressed some disappointment that the battle was dominating the conversations. His remark was an indication of weariness with the battle and its impression throughout the globe.

In an opening video deal with to the diplomats, Mr. Modi mentioned that whereas he understood that discussions “are affected by the geopolitical tensions of the day” — a transparent reference to the battle — he hoped the members would hold the deal with international crises affecting the various growing nations of the world. He cited financial downturns, local weather change and the pandemic.

Mr. Modi and different leaders in Asia and Africa have expressed rising frustration over the financial results of the battle, together with surging meals and power costs. Mr. Blinken heard about a few of these considerations throughout his visits this week to Kazakhstan and Uzbekistan — the primary by any Biden cupboard official to the previous Soviet republics of Central Asia, which Moscow sees as inside its sphere of affect.

The Group of 20 officers, together with Mr. Lavrov and Mr. Qin, did all comply with language within the last declaration saying the international locations would attempt to enhance and proceed the Black Sea Grain Initiative, which permits cargo ships carrying Ukrainian grain to go by way of a Russian naval blockade. The blockade had contributed to meals shortages and rising costs around the globe, which eased after the deal, brokered by Turkey and the United Nations, took impact in July.

That settlement expires in March, however Mr. Lavrov’s consent to the assertion about it within the declaration hinted that Moscow may comply with renew it. Nevertheless, U.S. officers say Russia continues to be slowing the shipments by hobbling inspections that happen when the ships attain Istanbul.

Because the battle started, the U.S. protection secretary, Lloyd J. Austin III, has spoken by cellphone a couple of occasions with Russia’s protection minister, Sergei Ok. Shoigu. However Mr. Blinken and Mr. Lavrov have had only one such name, final summer season, a couple of U.S. authorities supply to Russia to free Mr. Whelan and Brittney Griner, Individuals who the Biden administration says had been wrongfully convicted and imprisoned in Russia.

In December, the US launched Viktor Bout, an imprisoned Russian weapons supplier, in change for Ms. Griner, a basketball star sentenced to 9 years in a labor camp for hashish possession. The Biden administration has continued to press Russia to free Mr. Whelan.

Mr. Blinken and Mr. Lavrov have been in different worldwide conferences collectively and sat in the identical room over the previous yr. However they’ve often prevented one another, as they did at a Group of 20 assembly final summer season in Bali, Indonesia, and at a gathering of overseas ministers of Southeast Asian nations and companions in Cambodia.

Final month, at a gathering in India of Group of 20 finance ministers, the U.S. Treasury secretary, Janet L. Yellen, confronted Russian officers in a bunch assembly and mentioned that they had a “ethical crucial” to finish the battle. She additionally instructed them they had been “complicit in Putin’s atrocities.”

On the Thursday information convention, Mr. Blinken repeated his warning that China was contemplating supplying weapons to Russia to be used in Ukraine. He mentioned officers from U.S. allies and companion nations had confronted Chinese language counterparts over this, together with right here on the New Delhi convention. And he mentioned the US and people international locations may impose financial sanctions “of assorted varieties” if China had been to ship weapons.

The highest diplomats from a partnership of Asia-Pacific nations known as the Quad — the US, India, Japan and Australia — are scheduled to fulfill on Friday. One nation is predicted to dominate that dialog: China.

Mujib Mashal contributed reporting from New Delhi, and Nick Cumming-Bruce from Geneva.