The former British Prime Minister made a surprise return to government in Monday's cabinet reshuffle.
British Foreign Secretary David Cameron met Ukrainian President Volodymyr Zelenskyy on Thursday in his first overseas trip in his new job and pledged to continue providing military support for Ukraine's war effort for "however long it takes."
Cameron, a former prime minister who returned to government in a surprise appointment on Monday in a Cabinet reshuffle, said he wanted to make the trip to Kyiv his first diplomatic visit.
"I admire the strength and determination of the Ukrainian people," he told Zelenskyy, according to a video posted by the president.
Cameron said the UK would continue to provide moral and diplomatic support "but above all, the military support that you need not just this year and next year but however long it takes."
Zelenskyy thanked Cameron for visiting. Zelenskyy has tried to keep the world's focus on Ukraine's fight as attention has turned to the Middle East and Israel's war against Hamas.
"A good meeting," Zelenskyy wrote on Telegram. "Weapons for the front, strengthening of air defence, protection of our people and critical infrastructure. I am grateful to the UK for its support!"
The UK has been one of the strongest supporters of Ukraine in defending itself from Russia.
As of last month, the UK said it was second to the US in providing military funds to Ukraine, giving £4.6 billion ($5.7 billion) worth of assistance and training 30,000 Ukrainian troops on British soil.