The very public argument between President of the United States Donald Trump and his Ukrainian counterpart Volodymyr Zelensky was the "opposite of diplomacy", and the damage it has caused will be "hard to repair", and it remains to be seen whether Washington will stop sending weapons to Kyiv, analysts said.

The heated exchange flared up in the Oval Office in the White House on Friday over differing visions of how to end the Russia-Ukraine conflict. European leaders reacted by overwhelmingly voicing support for Zelensky, offering near-unanimous backing.

A meeting of European leaders took place in London on Sunday for crisis talks that seek to boost security cooperation and support for Ukraine.

The meeting at the White House on Friday between Trump — who was joined by Vice-President JD Vance — and Zelensky developed into a shouting match while the television cameras rolled.

Trump accused Zelensky of "gambling with World War III" and claimed Ukraine lacked the "cards" to fight Russia, while Vance labeled him disrespectful and ungrateful.

Trump later declared on social media X that Zelensky is "not ready for Peace if America is involved".

Zelensky departed the White House less than three hours after he arrived, canceling lunch and a scheduled news conference. A highly anticipated rare earth minerals deal was also not signed.

Public response

Meanwhile, in central Kyiv on Saturday, stunned Ukrainians were still coming to terms with how the talks between the two presidents had gone, according to Euronews. "I'm quite shocked by all of this," said 23-year-old chef Daniel Novak. "But for now, I understand that Zelensky is doing his best, that he is holding on."

Ukrainians, hardened by three years of conflict, rallied around Zelensky but also expressed concern over future US backing for Kyiv. "I doubt that we could stand without American help. They have helped us a lot with weapons and money. Maybe Europe will help us," Kyiv resident Liudmyla Stetsevych, 47, told Reuters.

US State Department spokeswoman Tammy Bruce said what many saw as Trump, Vance and Zelensky sparring in public was "diplomacy in action with blunt talk and a clarity that you rarely, rarely see … part and parcel of what it means to make America great again".

However, not everyone agreed. "Public debates like those are the opposite of diplomacy in action. In my view, the relation had soured before the meeting, which only confirmed that fact," Stanley Renshon, a political scientist at the City University of New York, said on Saturday.

"The relation will not improve but continue as it now is," Renshon told China Daily. "All that is left to watch for now is the ongoing charade."

Cal Jillson, a political scientist and historian at Southern Methodist University in Dallas, said that inviting reporters and cameras into the Oval Office and then dressing down a "beleaguered wartime ally" was not diplomacy.

"The damage created by such a public break will be hard to repair. Trump will require more access to Ukrainian minerals; he and Vance will require that Zelensky crawl, and he seems unwilling to do that. But pressure on him will build," Jillson said in an email.

Jillson added that one of the things to watch for in the coming weeks would be "how fast and fully the major European states move to fill the intelligence and material gaps left as American assistance declines".

For James M. Lindsay, a senior fellow in US foreign policy and director of Fellowship Affairs at the Council on Foreign Relations, the main thing to watch for is whether Trump cuts US weapons shipments to Ukraine.

Lindsay said the "acrimonious" meeting with Zelensky that culminated in the Ukrainian president being asked to leave the White House "has no precedent", as heads of government generally do not bicker in front of the cameras.

The researcher said in a note posted right after Friday's meeting that although Trump said that he might reduce US military aid to Ukraine once in office, that has yet to happen.

"Ukraine's ability to hold off Russia depends on maintaining the flow of US weapons. Everything changes if that stops," Lindsay wrote.

"Europe cannot make up the shortfall. So while the rhetorical fireworks between Trump (and Vance) and Zelensky grab the headlines — Trump himself said that today's meeting made for 'great television' — deeds matter more than words," he added.