The US is "destroying" the established world order, Ukraine's ambassador to the UK has claimed.

Valerii Zaluzhnyi said the White House had "questioned the unity of the Western world" and was "taking more and more steps towards" Russia, which launched a full-scale invasion of Ukraine in 2022.

The comments come as the US puts pressure on Ukraine to make concessions ahead of any peace talks, and after a public clash between Ukrainian President Volodymyr Zelensky and his US counterpart Donald Trump.

Zelensky has since said he is "ready to work" under Trump's "strong leadership", an apparent cooling in tensions welcomed by Trump - and which comes after the US paused military aid to Kyiv.

But Mr Zaluzhnyi's remarks at a conference at Chatham House in London on Thursday suggest there remains discontent over the US's actions.

He told an audience: "We see that it is not only Russia and the axis of evil trying to destroy the world order, but the US is actually destroying it completely".

The Ukrainian envoy added that talks between the US and Russia - the latter of which was "headed by a war criminal" in President Vladimir Putin - showed the White House was making "steps towards the Kremlin regime, fully realising that in this case Europe could be a new target for Russia".

Mr Zaluzhnyi, who took over as Kyiv's ambassador to London in 2024 following three years as commander-in-chief of the Ukrainian armed forces, also suggested that Nato could cease to exist as a result of Washington's change in posture.

While Zelensky has expressed a wish to bring the war in Ukraine to an end swiftly, Kyiv has voiced concerns about the Trump administration's handling of talks and the concessions to Moscow that may be made without firm security guarantees for Ukraine.

Trump vowed during the US election campaign to bring the war to an end quickly, and preliminary US-Russian talks were held in Saudi Arabia last month - without European or Ukrainian representatives present.

The US's decision to halt its military assistance to Ukraine and intelligence sharing has been cast by Trump administration officials as a means of getting Kyiv to co-operate with the US-led peace talks.

Any corresponding pressure the US has been putting on Moscow to make concessions has not been made public.

Zaluzhnyi said the pause in intelligence sharing, as well as an earlier decision to oppose a UN resolution condemning Russian aggression in Ukraine, were "a huge challenge for the entire world".

His comments come as Politico reports that members of Trump's team held discussions with some of Zelensky's political opponents, after Trump allies suggested the Ukrainian president should stand aside as his term expired in May.

Citing unnamed sources in the US and Ukraine, it says talks were held with opposition leader Yulia Tymoshenko and senior members of Petro Poroshenko's party, who preceded Zelensky as president.

Independent opinion polls in Ukraine suggest Zaluzhnyi has the most public support with at least 70%, Zelensky has 57% support, and Poroshenko about 20%. Tymoshenko and Poroshenko both have their own red lines and share a pro-European stance.

Responding to the report, Tymoshenko said her team was talking with "all allies who can help ensure a just peace as soon as possible", while noting elections cannot be held under Ukraine's constitution while it is under martial law.

Poroshenko wrote in a lengthy statement that his party worked "publicly and transparently" with the US, and that meetings have focused on supporting Ukraine's war effort.

While criticising Zelensky's government over its political decisions and communications with the US, he too stressed that elections could only take place after a ceasefire was signed.

While the Politico article suggested the Trump administration may be seeking an alternative to Zelensky, these meetings appear to be long-standing and predate both the war and the recent straining of ties with the US.