London talks aimed at securing a ceasefire between Ukraine and Russia have been downgraded and will no longer include US Secretary of State Marco Rubio and special envoy Steve Witkoff.

The meeting on Wednesday will instead take place among senior officials from the UK, France, Germany, Ukraine, and the US, while UK Foreign Secretary David Lammy will host a bilateral meeting with his Ukrainian counterpart.

Trump's Ukraine envoy, Gen Keith Kellogg, is attending the talks instead of Witkoff and Rubio, who referred to Wednesday's talks as "technical meetings".

The US secretary of state will instead focus on talks in Moscow this week, as the pace of diplomatic efforts to end the war quickens.

There is growing speculation that Russia might be willing to halt its invasion along current front lines in return for significant concessions.

However, there is little clarity about where the latest talks are heading or whether they will succeed.

Ukrainian President Volodymyr Zelensky has ruled out recognising occupied Crimea as Russian territory, after reports suggested this was being considered by the US and the Kremlin.

Russia intensified its attacks on Ukraine on Wednesday, after a brief lull over Easter when it halted air strikes.

Nine people were killed and dozens more wounded in the eastern Ukrainian city of Marhanets when a Russian drone hit a bus carrying workers.

Officials in the southern region of Kherson said a key facility supplying electricity had been destroyed after coming under repeated Russian attack.

The UK Foreign Office confirmed on Wednesday that talks between foreign ministers had been postponed. "Official level talks will continue but these are closed to media," the statement said.

British diplomats said they were not entirely clear why Rubio and Witkoff had pulled out of the London talks.

The US state department blamed logistical reasons, but it was clear the decision was last-minute and left the Foreign Office wrongfooted.

Marco Rubio spoke to the UK foreign secretary on Tuesday evening about what he hoped would be "substantive and good technical meetings", adding that he would reschedule his planned trip to UK in the coming months.

Lammy called the conversation "productive", taking place ahead of a "critical moment for Ukraine, Britain and Euro-Atlantic Security" as "talks continue at pace".

The US secretary of state said on X: "I look forward to following up after the ongoing discussions."

The US decision may have been because the Americans felt they had nothing new to say since they last met in Paris last week - or they may have realised the Ukrainians were likely to reject the latest US ceasefire plan and did not want to hear bad news.

The White House said Witkoff would travel to Moscow this week for his fourth meeting with Russian President Vladimir Putin.

All this comes amid a report in the Financial Times that Russia might be ready to halt its invasion along existing front lines and give up territorial claims to areas it does not currently occupy, in return for US recognition of Russian sovereignty over Crimea.

Kremlin spokesman Dmitry Peskov rejected the report, telling state media that "a lot of fakes are published nowadays".

Zelensky said no such proposals had been shared with him and he rejected recognising Crimea as Russian territory.

"Ukraine does not legally recognise the occupation of Crimea. There's nothing to talk about," he said during a news briefing on Tuesday night.

Recognising Russia's illegal annexation of Crimea would not only be politically impossible for Zelensky to accept, it would also be contrary to post-war international legal norms that borders should not be changed by force.

Speaking to BBC Radio 4's Today programme, Yuriy Sak, an adviser to Ukraine's ministry of strategic industries, said it was "not productive to discuss" such reports and added it was "na?ve" to expect Ukraine to change its position on "non-negotiable" issues such as Crimea.

Sak added that Ukrainian negotiators would attend the London meeting on a "very clear, narrow mandate" to achieve a ceasefire that will "pave the way for further talks".

Putin called a temporary ceasefire for the Easter weekend but UK Defence Secretary John Healey told the House of Commons on Tuesday that British military intelligence had found no evidence of a let-up in attacks.

"While Putin has said he declared an Easter truce, he broke it," he said. "While Putin says he wants peace, he has rejected a full ceasefire and while Putin says he wants to put an end to the fighting, he continues to play for time in the negotiations."

Healey added that he could "confirm Russian military progress" was "slowing" while the country continued to "pressure Ukraine on a number of fronts".

It is estimated that hundreds of thousands of people have been killed or injured on all sides since Russia invaded Ukraine on 24 February 2022, and nearly seven million Ukrainians are currently listed as refugees worldwide.

The conflict goes back more than a decade, to 2014, when Ukraine's pro-Russian president was overthrown. Russia then annexed Crimea and backed militants in bloody fighting in eastern Ukraine. (BBC)

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