European leaders threw their support behind Ukrainian President Volodymyr Zelensky after his spat with Donald Trump sent shockwaves across the world, casting doubts over efforts to end the Russia-Ukraine war.

The US president openly berated Zelensky on Friday for not being "thankful", and later accused the Ukrainian leader of "not being ready for peace" and having "disrespected" the United States in the "cherished Oval Office".

Here are some of the political reactions from around the world.

EU: 'world needs new leader'

European Union chiefs Ursula von der Leyen and Antonio Costa assured Zelensky that he was "never alone".

"Be strong, be brave, be fearless," wrote the European commission and council presidents in a joint statement on social media, telling Zelensky: "We will continue working with you for a just and lasting peace."

The bloc's top diplomat Kaja Kallas questioned the United States leadership of the transatlantic alliance between European powers and Washington.

"Today, it became clear that the free world needs a new leader. It's up to us, Europeans, to take this challenge," she wrote on social media.

France: Russia the 'aggressor'

French President Emmanuel Macron said that Russia was the "aggressor" in the Ukraine war.

"There is an aggressor which is Russia. There is an aggressed people which is Ukraine," Macron told journalists, adding: "We were all right to help Ukraine and sanction Russia three years ago and to continue to do so."

He later went further to say that "if anyone is playing at World War III, it's Vladimir Putin", referring to Trump's accusations against Zelensky.

Germany: don't 'confuse'

Germany's likely next chancellor Friedrich Merz assured his support to Zelensky.

"We must never confuse the aggressor and the victim in this terrible war," Merz said. The outgoing Chancellor Olaf Scholz also voiced support for Ukraine, as did Foreign Minister Annalena Baerbock, who added that Kyiv's "quest for peace & security is ours".

Hungary: Trump stood for 'peace'

Hungarian Prime Minister Viktor Orban, one of the closest partners of both Trump and Russian President Vladimir Putin, thanked Trump for standing "bravely for peace".

"Strong men make peace, weak men make war," Orban posted on X.

Italy: summit needed

Italian Prime Minister Giorgia Meloni called for the United States, Europe and their allies to gather over the Ukraine war.

"A summit without delay is needed... to talk frankly about how we intend to tackle today's major challenges, starting with Ukraine, which together we have defended in recent years," she said.

Netherlands: support 'undiminished'

"Dutch support for Ukraine remains undiminished. Especially now," Prime Minister Dick Schoof said on X, adding "we want lasting peace and an end to the war of aggression that Russia has started."

Poland: 'not alone'

Staunch Kyiv ally Poland moved to reassure Ukrainians after the dispute.

"Dear Ukrainian friends, you are not alone," Polish Prime Minister Donald Tusk said on X in a post addressed to Zelensky.

Spain: 'stands with' Ukraine

Spanish Prime Minister Pedro Sanchez said his country would stand by war-torn Ukraine after the row.

"Ukraine, Spain stands with you," Sanchez, a staunch backer of Ukraine since Russia's 2022 invasion who pledged one billion euros of aid in a visit to Kyiv this week, wrote on X.

Russia: 'cocaine clown' Zelensky

"For the first time, Trump told the truth to the cocaine clown's face," said former president Dmitry Medvedev, now deputy chairman of Russia's security council, referring to Zelensky.

Kirill Dmitriev, one of Moscow's negotiators in the first high-level talks between Russian and US officials since the Kremlin sent troops into Ukraine, branded the spat between the two leaders as "historic".

UK: 'unwavering support'

British Prime Minister Keir Starmer vowed "unwavering support" for Ukraine and spoke to both Trump and Zelensky following their meeting.

Starmer "is doing all he can to find a path forward to a lasting peace based on sovereignty and security for Ukraine", a Downing Street spokesperson said.

Ukraine: Zelensky was 'right'

Ukraine's Prime Minister Denys Shmygal said Zelensky was "right" as "peace without guarantees is not possible".

"Ceasefire without guarantees is the way to Russian occupation of the entire European continent," Shmygal said.

Army chief Oleksandr Syrsky, who rarely makes political statements, affirmed the armed forces stood behind Zelensky, while calling for unity.

US Democrats: Trump 'doing Putin's work'

Senate Democrats accused Trump and his Vice President JD Vance of siding with Putin.

"Trump and Vance are doing Putin's dirty work," Democratic Senate minority leader Chuck Schumer posted on social media.

Other Ukrainian allies

Other Ukrainian allies also rallied behind Zelensky, with Canada saying Kyiv was not only fighting for its freedom but also "ours".

Denmark described its "pride" in supporting Ukraine while Sweden referred to Ukrainians as "friends".

Australian Prime Minister Anthony Albanese said his country will "stand with Ukraine" for as long as needed while New Zealand's Prime Minister Christopher Luxon praised Ukraine as "a proud, democratic and sovereign nation".

Swiss President Karin Keller-Sutter said her country was "firmly committed to supporting a just and lasting peace, while condemning Russia's aggression against a sovereign state".

AFP