Ukrainian President Volodymyr Zelenskyy shakes hands with Estonian President Alar Karis next to Estonian Prime Minister Kaja Kallas after giving a speech to the Riigikogu, or Estonian Parliament, in Tallinn on Jan 11, 2024. [AFP]

British Prime Minister Rishi Sunak traveled to Kyiv Friday, where he unveiled nearly $3.2 billion in new military funding for Ukraine, Britain's largest annual commitment since Russia first invaded the country.

Speaking at a joint news conference with Ukrainian President Volodymyr Zelenskyy, Sunak said the two countries also signed a long-term bilateral security agreement that he said will form the core of a partnership between their countries that "will last a hundred years or more."

Sunak said the agreement was the first in a series of "security assurances" promised by NATO allies during the alliance's summit last year in Vilnius, Lithuania.

Zelenskyy said with the signing of the agreement that "the history of Europe changed today." He called it "unprecedented" and said it will provide a basis for working with other partners in the future.

Sunak said the military aid package will include air defense equipment, anti-tank weapons, long-range missiles, ammunition and artillery shells, along with training for Ukrainian servicemen and women.

The British prime minister said it also includes $255 million for drones - what he said was "the single largest package of drones given to Ukraine by any nation."

Sunak said he sought to send a message to Ukraine on behalf of his nation and Ukraine's allies around the world that they will never be alone. He said the war in Ukraine is about the nation's right to defend itself and to be an independent democracy.

"If [Russian President Vladimir] Putin wins in Ukraine, he will not stop there," Sunak said. He said wavering in support of Ukraine will embolden Putin and his allies in North Korea, Iran and elsewhere.

Zelenskyy seeks support in Baltics

Sunak's visit comes a day after Zelenskyy made a tour of Baltic nations Estonia, Lativa and Lithuania, where he sought support for Ukraine's ongoing war with Russia.

In the Latvian capital of Riga on Thursday, Zelenskyy said that Moscow's plan was to make tactical advances on the battlefield ahead of the presidential election and that Russia would then take larger military action.

Earlier on Thursday during his visit to Estonia, Zelenskyy said a pause in Russia's war against Ukraine would benefit only Russia by allowing it to boost its supply of munitions and "run us over."

"A pause on the battlefield on the territory of Ukraine is not a pause in war. It is not the end of war," Zelenskyy said.

"It doesn't lead to political dialogue with the Russian Federation or with someone else. This pause will only benefit the Russian Federation," he said.

The Ukrainian leader said Wednesday in the Lithuanian capital, Vilnius, that his country's forces have shown the world that Russia's military can be stopped but that the Kyiv government badly needs Western allies to send it more air defense systems to shoot down an increased barrage of Russian drones and missiles.

He acknowledged, however, that the stockpiles are low in countries that could assist Ukraine.

"Warehouses are empty," Zelenskyy said. "And there are many challenges to world defense."

U.S. aid still on hold

In the United States, White House national security spokesperson John Kirby on Thursday said U.S. assistance for Ukraine's war effort has stopped amid ongoing negotiations in Washington over an aid package.

"The assistance that we provided has now ground to a halt," Kirby said.

Although U.S. aid to Ukraine has stopped for the time being, the U.S. State Department on Thursday imposed sanctions over the transfer of North Korean ballistic missiles to Russia for use in its war against Ukraine, Secretary of State Antony Blinken said.

"We will not hesitate to take further actions," Blinken said in a statement announcing the sanctions against three Russian entities and one individual.