The Kremlin has denied Donald Trump spoke with Vladimir Putin in a phone call the day after the presidential election.
The US president-elect reportedly urged the Russian president not to escalate the war in Ukraine and reminded him of America's sizeable military presence in Europe during the conversation on Thursday, according to The Washington Post and Reuters, citing sources familiar with the call.
According to several other sources, the pair went on to discuss the goal of peace on the continent, as well as the prospect of a further call soon to look into the resolution of the conflict in Ukraine.
Follow live: Putin has no plans to speak to Trump
But on Monday, the Kremlin denied the reports and spokesman Dmitry Peskov said Mr Putin has no specific plans to speak to Mr Trump at present.
"This is completely untrue. This is pure fiction, it's just false information," Mr Peskov said. "There was no conversation."
Asked if Mr Putin had plans for any contact with Mr Trump, Mr Peskov said: "There are no concrete plans yet."
On Friday, the Kremlin said Mr Putin was ready to discuss Ukraine with Mr Trump - but that did not mean he was willing to alter Moscow's demands - namely that Ukraine drops its ambitions to join NATO and surrenders the four territories currently held by Russia.
The Washington Post said two sources indicated the Ukrainian government was informed of the call between Mr Trump and Mr Putin - and did not object to the conversation taking place.
We simply do not know what Trump's policy on Ukraine will be
If the reports of this call are correct - that Donald Trump urged Vladimir Putin not to escalate the conflict - it's certainly not the pro-Russia rhetoric Ukraine feared it would be hearing.
But will it ease their concerns about a potential cut to US military aid and being forced into a peace deal? Unlikely.
That's because, if true, it is contact between the Russian president and the US president-elect.
It will fuel anxiety in Kyiv and other European capitals over how the relationship between the two develops.
They got on well last time, too well in the eyes of many Western officials, and the fear is they will do so again.
The Kremlin has denied the reports of the call, insisting no conversation took place.
But it also said last week that Mr Putin had no plans to congratulate Mr Trump. And then he did.
In fact, he was highly complementary of the president-elect, praising his bravery during the attempt on his life.
The bottom line, I think, is that Moscow, Kyiv, London et al simply don't know what Mr Trump's policy on Ukraine will actually be.
Yes, he's vowed to bring the war to a swift conclusion, but he hasn't said how he’ll do that or what peace will look like.
So right now, there is a charm offensive going on, from both sides.
Kyiv and its allies, including the UK, are hoping to persuade Mr Trump not to abandon their cause, while Moscow is trying to appeal to his image as a dealmaker, advocating a peace agreement on its terms.
However, Ukraine's foreign ministry said it was "impossible" that Ukraine would have endorsed such a call and that reports otherwise were "false".
When asked about the call, Mr Trump's communications director Steven Cheung said: "We do not comment on private calls between President Trump and other world leaders."
Meanwhile, US President Joe Biden, who will hand over power on 20 January, will warn Mr Trump and Congress not to abandon Ukraine, according to one of the president's top officials.
The president-elect and sitting president will meet on Wednesday in the Oval Office, a week after Mr Trump beat Democratic nominee Kamala Harris in the election.
In an interview with CBS News, national security adviser Jake Sullivan said: "President Biden will have the opportunity over the next 70 days to make the case to the Congress and to the incoming administration that the United States should not walk away from Ukraine, that walking away from Ukraine means more instability in Europe."
Under Mr Biden, Washington has provided tens of billions of dollars of military and economic aid to Ukraine - funding that Mr Trump, and some of his supporters, have repeatedly criticised and rallied against.
Mr Trump insisted last year that Mr Putin never would have invaded Ukraine if he had been in the White House at the time and has repeatedly said he could settle the war "in one day" if he was re-elected again.
On Sunday night, Ukrainian President Volodymyr Zelenskyy said strength and diplomacy must work together to bring the two-and-a-half-year war to an end.
"We understand very clearly that diplomacy has no prospects without strength," he said.
"But without a clear understanding of diplomatic goals, weapons alone will not do the job. That's why strength and diplomacy must work hand in hand."
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It comes as both Russia and Ukraine launched "record" drone attacks on each other overnight on Saturday, injuring a woman and temporarily halting air traffic at some of Russia's busiest airports.
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Russia launched 145 drones overnight, according to Ukraine, 62 of which were shot down, as the two countries attacked each other.
Russia's defence ministry said 70 drones were shot down in its territory, including 34 over the outskirts of the capital Moscow.