Russia cannot accept U.S. proposals to end the war in Ukraine in their current form because they do not address problems. The comments by Deputy Foreign Minister Sergei Ryabkov suggest Moscow and Washington have so far been unable to bridge differences which President Vladimir Putin raised more than two weeks ago when he said U.S. proposals needed reworking.

Trump in recent days has said he is “pissed off” with Putin and has spoken of imposing sanctions on countries that buy Russian oil if he feels Moscow is blocking a deal. Putin has said he wants Ukraine to drop its ambitions to join NATO, Russia to control the entirety of four Ukrainian regions it has claimed as its own, and the size of the Ukrainian army to be limited. Kyiv says those demands are tantamount to demanding its capitulation.

Asked about Trump’s latest remarks about wanting Putin to do a deal on Ukraine, Kremlin spokesman Dmitry Peskov told reporters earlier on Tuesday that Moscow was “continuing our contacts with the American side”.

“The subject is very complex. The substance that we are discussing, related to the Ukrainian settlement, is very complex. This requires a lot of extra effort.” Russia also said on Tuesday it was fully complying with a U.S.-brokered moratorium on attacking Ukraine’s energy facilities.

Russian Foreign Minister Sergei Lavrov told state TV that Defence Minister Andrei Belousov had briefed Putin on alleged Ukrainian violations during a meeting of Russia’s Security Council on Tuesday. Russia passed a list of the violations to U.S. National Security Adviser Mike Waltz and Secretary of State Marco Rubio, Lavrov said.