LONDON, Dec 8, 2025 (BSS/AFP) - British Foreign Secretary Yvette Cooper will meet her American counterpart Marco Rubio in Washington on Monday, the UK Foreign Office announced, amid intensified diplomatic efforts aimed at ending the war in Ukraine.

The visit -- her first to the US capital since becoming Britain's top diplomat in September -- comes as Prime Minister Keir Starmer hosts Ukrainian President Volodymyr Zelensky and the leaders of France and Germany in London.

Monday's meetings follow days of talks last week between Ukrainian and US officials in Miami over a US-led plan to end the nearly four-year war in Ukraine, Europe's deadliest in eight decades.

Zelensky said Saturday he and his negotiating team had had a "very substantive and constructive" call with US envoys Steve Witkoff and Jared Kushner.

Announcing Cooper's Washington visit, the Foreign Office in London said "the UK and US will reaffirm their commitment to reaching a peace deal in Ukraine".

It noted Britain supports "President Trump's ongoing efforts to secure a just and lasting peace".

The transatlantic allies' talks are set to also focus on the situation in Gaza, and "cover US efforts to sustain the ceasefire and make progress on President Trump's peace plan," London added.

The fragile US-backed ceasefire and hostage deal, which came into effect in October, ended two years of full-scale fighting set off by the October 7, 2023 Hamas attack on Israel.

Despite the ceasefire, more than 350 Palestinians have been killed in Gaza, according to local health authorities, as well as three Israeli soldiers.

Israeli Prime Minister Benjamin Netanyahu said Sunday that he expected to move into the second phase of the US-sponsored ceasefire plan for Gaza "very shortly", noting it is "is more difficult".

The UK Foreign Office said Cooper will also discuss the ongoing conflict in Sudan and "the urgent need to press the warring parties to agree to a humanitarian truce, the prevention of atrocities and humanitarian access".

Separately on Sunday, Cooper announced London will host a major international summit next summer to tackle global "flows of dirty money".

The June 23-24 Illicit Finance Summit at Lancaster House will convene governments, civil society and private sector representatives, including major banks, to discuss strengthening global enforcement efforts to "prevent, disrupt and recover dirty money".