Russia believes the United States is deeply involved in Ukrainian attacks against it and has raised the issue with Washington, Foreign Minister Sergei Lavrov said in comments broadcast on Friday.
He said that the alleged U.S. support included the supply of intelligence.
"We have submitted a series of questions to the State Department requesting comment, including on the matter of intelligence data and the fact that the U.S. is far more deeply involved in organizing and executing strikes deep within Russian territory against civilian targets. We await a response," Lavrov told state TV.
No immediate comment was available from the U.S. side.
No peace talks on Ukraine have taken place since February, when the U.S. went to war with Iran and broke off its efforts to mediate between Moscow and Kyiv.
Lavrov quoted Putin as telling U.S. President Donald Trump at a summit one year ago that Moscow was ready to support U.S. peace proposals.
He quoted Putin as saying: "Donald, you sent us proposals, and I’ve given them some thought. There are matters that require compromise. But I accept your proposals in the form you sent them to me."
U.S. Secretary of State Marco Rubio has denied that any agreement was reached at the summit, saying that if it had been, the war would now be over.
Lavrov said Putin was willing to receive Trump's envoys on Ukraine if they came to Russia again. "The question is what they will be bringing with them."
He also said Moscow would intensify its efforts to destroy any Western supplies to the Ukrainian military.
"We will make our methods much tougher in order to dismantle everything that fuels Kyiv's war machine from the West. And we are already doing this," Lavrov said.
