US National Security Adviser Jake Sullivan said on Monday that the Biden administration had “channels” of communications with the Russian Federation at senior levels, in hopes of reducing the risk for the use of nuclear weapons.
Mr Sullivan told the Economic Club of New York that Washington's channels of communication help to clarify “potential misunderstandings”.
He said they ensured Russia had “a very good understanding of where the United States stands, particularly on questions of risk reduction and issues like the consequences of the potential use of nuclear weapons".
Mr Sullivan said it had been some time since there was a phone conversation or a direct meeting between US President Joe Biden and Russian leader Vladimir Putin.
A report by The Wall Street Journal published on Sunday said Mr Sullivan held confidential talks in recent months with Kremlin aide Yuri Ushakov and Russian Security Council secretary Nikolai Patrushev, which were not disclosed publicly.
White House press secretary Karine Jean-Pierre declined to give clarification or more details on correspondence between Mr Sullivan and any officials in Moscow, but repeated the Biden administration's commitment to Ukraine.
"We reserve the right to speak directly at senior levels about issues of concern to the United States," Ms Jean-Pierre said.
"Our conversations have focused only on risk reduction and the US-Russia relationship. We continue to adhere to our basic principle of nothing about Ukraine without Ukraine.
Few high-level contacts between US and Russian officials have been made public in recent months as Washington has insisted that any talks on ending the war in Ukraine be held between Moscow and Kyiv.
The White House said Mr Biden still had no intention of meeting Mr Putin at this month’s G20 leader summit on November 15-16 in Bali, Indonesia, but insisted that Ukraine should be able to attend.
"We've been very clear from this podium, very clear about that if Russia gets to attend the G20, then so should Ukraine," Ms Jean-Pierre said.
"What I can guarantee you is the United States will show up and be be at the table. And we will be unapologetic in our defence of Ukraine and calling out Russia for its brutal war.
But Ukrainian President Volodymyr Zelenskyy said on Thursday that he would not take part in this month’s G20 summit if Mr Putin attended.