Britain's new defense secretary Grant Shapps met with Ukrainian President Volodymyr Zelensky on a surprise visit to Ukraine, Zelensky's office said Thursday.

"A meaningful meeting with Secretary of State for Defense Grant Shapps," Zelensky wrote on Telegram Thursday. "Thank you for your strong financial, defense, and humanitarian support for Ukraine! Our cooperation in the military sphere significantly enhances the capabilities of Ukrainian soldiers on the battlefield."

It's unknown when exactly Zelensky and Shapps met.

Zelensky said cooperation between both countries "allows the Ukrainian army to significantly expand its capabilities on the battlefield, in particular by means of long-range weapons," according to a statement from his office.

The two also discussed bolstering Ukraine's air defense, saying it is "particularly important in the run-up to the winter season," the statement said.