Ukraine's President Volodymyr Zelensky will on Wednesday make his first visit to the UK since the Russian military offensive began in his country, Britain said, announcing that it would offer fighter jet training to Ukrainian troops.

Zelensky will meet Prime Minister Rishi Sunak and address parliament, Sunak's office said, adding that the UK was planning "to train fighter jet pilots and marines" from the Ukrainian armed forces.

"The leaders will discuss a two-pronged approach to UK support for Ukraine, starting with an immediate surge of military equipment to the country to help counter Russia's spring offensive, and reinforced by long-term support," said a statement issued by Sunak's office.

"The prime minister will offer to bolster the UK's training offer for Ukrainian troops, including expanding it to fighter jet pilots to ensure Ukraine can defend its skies well into the future," it added.

A current programme had already trained 10,000 Ukrainian troops "to battle readiness" over the past six months and would train a further 20,000 this year. (AFP)