KYIV, April 27 - US President Donald Trump has said he thinks his Ukrainian counterpart Volodymyr Zelensky is willing to give up Crimea to Russia as part of a peace deal - despite Kyiv's previous rejections of any such proposal, BBC reported.

Asked if he thought the Ukrainian president was ready to cede control of its southern peninsula, which was illegally annexed by Russia in 2014, Trump replied: "I think so."

Trump also urged Russian President Vladimir Putin to "stop shooting, sit down and sign a deal" to end the fighting, suggesting this could be achieved within two weeks.

He made the comments to reporters after returning from the Vatican, where he held a brief meeting with Zelensky before Pope Francis' funeral.

Trump said that meeting had "gone well" and that Crimea had been discussed "very briefly".

He also said that Zelensky now seemed "calmer", in what could have been a reference to a very public clash between the two presidents at the White House in February.

Ukraine has repeatedly rejected making any territorial concessions, stressing that issues about land should only be discussed once a ceasefire is agreed.

Neither Zelensky nor Russian President Vladimir Putin have publicly responded to Trump's latest comments.

Earlier on Sunday, German Defense Minister Boris Pistorius warned Ukraine not to agree to a deal which involves sweeping territorial concessions in return for a ceasefire.

He told German public broadcaster ARD that Kyiv "should not go as far as the latest proposal by the American president", which he said would amount to a "capitulation".

The German minister said that Ukraine knew it might have to part with some territory to secure a truce.

"But they will certainly not go as far - or should not go as far - as the latest proposal by the American president.

"Ukraine could have got a year ago what was included in that proposal, it is akin to a capitulation. I cannot discern any added value," Pistorius said.

Trump said last week that "most of the major points [of the deal] are agreed to". Reports suggest that Ukraine could be asked to give up large portions of land seized by Russia, including Crimea.

The BBC has not seen the exact details of the latest US plan.

On Friday, Reuters news agency reported that it had seen proposals from the US that included American legal acceptance of Russia's illegal annexation of Crimea and de facto recognition of Russian control of other occupied areas, including all of Luhansk in the east of the country.

Reuters says it has also seen counter-proposals from Europe and Ukraine, which reportedly say the sides will only discuss what happens to occupied Ukrainian territory once a ceasefire has come into effect.

The US plan also rules out Ukraine's membership in the Nato military alliance and sees a UK-France led "coalition of the willing" providing a security guarantee once a ceasefire is in force without the involvement of the US.

Meanwhile the Europeans want the US to give "robust" guarantees in the form of a cast-iron Nato-style commitment to come to Ukraine's aid if it is attacked. (bbc/ez)