Donald Trump “will hurt America” if he allows Putin to win in Ukraine, Nato’s top military official has said.

In the strongest criticism of Mr Trump’s so-called peace plans since he won last week’s election, Adml Rob Bauer said Ukraine is of “strategic importance” to the US.

He also warned that North Korea’s entry into the war on Russia’s side was a “problem” for the US.

It came as the Kremlin welcomed what it said was Mr Trump’s openness to a deal that could bring an end to the war.

Dmitry Peskov, the spokesman for the Kremlin, said: “The signals are positive. Trump during his election talked about how he perceives everything through deals, that he can make a deal that can lead to peace.”

Last week, Mr Trump was reported considering a plan that would freeze the conflict on the current front lines, with European peace-keepers deployed to an 800-mile buffer zone.

On Saturday, Donald Jr, Mr Trump’s son, mocked Volodymyr Zelenksy on social media, resharing a video that said Ukraine’s financial “allowance” from the US is about to run out.

In his first term, Mr Trump threatened to pull the United States out of Nato, calling on European nations to increase their own defence spending rather than rely on the protection of America.