Sir Keir Starmer is under pressure to take a firm stance with Donald Trump during his visit to Washington next week, amid a series of unverified claims about Ukraine that have unsettled Western diplomatic relations.

Over the past week, the US president has exchanged heated remarks with Ukrainian leader Volodymyr Zelensky, accusing Kyiv of initiating the war and asserting that Russia controls the peace negotiations. Mr. Trump also referred to Mr. Zelensky as a "dictator," a claim that UK political figures, including Sir Keir, have rejected.

In response, Mr. Zelensky accused Mr. Trump of being influenced by Russian disinformation, prompting White House officials to criticize the Ukrainian leader for "insulting" the US president. The tensions escalated when a planned joint press conference in Kyiv was abruptly canceled, signaling a deepening rift between the two nations.

Adding to the controversy, businessman Elon Musk, who is advising Mr. Trump on federal spending, backed the US president’s disputed assertion that Mr. Zelensky’s popularity has plummeted. Mr. Musk described Ukraine’s leadership as a "fraud machine feeding off the dead bodies of soldiers."

Sir Keir's upcoming trip to the US will mark his first in-person meeting with Mr. Trump since his election as Prime Minister. The discussions are expected to include US support for Ukraine and potential peacekeeping efforts if a ceasefire is brokered.

However, growing voices are urging Sir Keir to directly challenge Mr. Trump on his remarks regarding Ukraine and US-Russia negotiations. Liberal Democrat leader Sir Ed Davey called on the Prime Minister to engage “honestly and openly” with Mr. Trump, emphasizing the serious threats the US leader poses to global security and economic stability.

Sir Ed also pushed for the UK to accelerate its commitment to increasing defense spending to 2.5% of GDP, suggesting that a hike in the digital services tax from 2% to 10% on multinational corporations could fund the increase.

European countries have been under pressure from the US to enhance their defense budgets, leading to a recent meeting of European leaders aimed at addressing security concerns. Meanwhile, American and Russian officials held preliminary discussions in Saudi Arabia on resolving the conflict—without any Ukrainian representatives present.

Following a G20 foreign ministers' meeting in Johannesburg, South Africa, UK Foreign Secretary David Lammy expressed skepticism about Russia's willingness to engage in serious negotiations. He noted that Russian Foreign Minister Sergei Lavrov’s remarks lacked any real commitment to peace.

During the closed-door session, Mr. Lammy accused Moscow of perpetuating "tired fabrications" and urged an end to "tsarist imperialism." In contrast, Mr. Lavrov reportedly refused to attend Mr. Lammy’s speech.

The G20 discussions will continue into Friday, with Mr. Lammy set to hold bilateral talks with officials from South Africa, Saudi Arabia, and Singapore.

Meanwhile, Sinn Féin leaders have announced they will boycott a White House event in protest against the potential mass displacement of Palestinians in Gaza. Party president Mary Lou McDonald and Northern Ireland First Minister Michelle O’Neill stated their decision on Friday, citing a "principled stance."

Sinn Féin representatives traditionally visit the US around St. Patrick’s Day, coinciding with the Irish prime minister’s annual invitation to meet the US president.