LONDON -- The White House said it's is "very optimistic" ahead of special envoy Steve Witkoff's meeting in Moscow on Tuesday with Russian President Vladimir Putin, as U.S. officials continue their push to end Russia's war against Ukraine.

President Trump's son-in-law, Jared Kushner, and U.S. special envoy Steve Witkoff met with Russian President Vladimir Putin​ in Moscow on Tuesday, amid a push by Mr. Trump to end the war in Ukraine.

Witkoff, the man whom Washington has sent to negotiate with Putin this week, is viewed with suspicion by Kyiv and its allies after a leaked phone call suggested he was advising Moscow on how to deal with Trump, according to a transcript published by Bloomberg News.

President Vladimir Putin warned European powers on Tuesday that if they started a war with Russia then Moscow was ready to fight and that the defeat of European powers would be so absolute that there would be no one left to even negotiate a peace deal.

Putin also claimed that Zelensky’s European allies have pushed for demands that are “absolutely unacceptable."

The Russian leader accused Kyiv’s European allies of trying to undermine peace talks by amending a U.S. peace plan devised with Kremlin input, in remarks ahead of a meeting with White House special envoys Steve Witkoff and Jared Kushner.

U.S. special envoy Steve Witkoff is meeting with Russian President Vladimir Putin to discuss a peace plan that Washington hopes can end the nearly four-year war in Ukraine.

Russian President Vladimir Putin signed an order to allow visa-free entry into the country for Chinese citizens as ties between the two nations continue to deepen.