US Secretary of State Antony Blinken met with Russian Foreign Minister Sergey Lavrov for the first time since Moscow launched its invasion of Ukraine.
US officials said Mr Blinken and Mr Lavrov chatted for roughly 10 minutes on the sidelines of the G20 conference in New Delhi.
A senior US official who spoke to reporters on condition of anonymity to discuss the private conversation, said Blinken had “disabused” Lavrov of any idea they might have that US support for Ukraine is wavering.
Russia had no immediate comment on the substance of the conversation.
It comes as Ukraine has rejected claims by Vladimir Putin that “saboteurs” are carrying out a “terrorist act” in the Russian region of Bryansk.
Kremlin officials are claiming that its forces are battling a Ukrainian “sabotage group” alleged to have infiltrated Russian territory and taken hostages, with Mr Putin said to be receiving updates on the situation.
But Mykhailo Podolyak, a presidential aide to Ukraine’s Volodymyr Zelensky, rejected Russia’s claims as “a classic deliberate provocation” by Moscow.