President Volodomyr Zelensky met with Britain's King Charles on July 18, and in a post on social media thanked the U.K. for being "one of Ukraine's closest and most important allies."
Zelensky was in the U.K. to attend the Fourth European Political Community summit, held at Blenheim Palace, near Oxford.
"I am grateful to His Majesty King Charles III of the United Kingdom of Great Britain and Northern Ireland for today’s audience," Zelensky said on social media after the meeting.
"The United Kingdom remains one of Ukraine's closest and most important allies. We appreciate all the support provided to the Ukrainian people."
After arriving in Britain in the morning, Zelensky was met off the plane by Valerii Zaluzhnyi, Ukraine's former commander-in-chief and recently appointed ambassador to the U.K.
Later in the day, Zelensky signed 10-year bilateral security agreements with the Czech Republic and Slovenia.
Prague and Ljubljana will provide Ukraine with long-term military and non-military assistance, according to the agreements.
Czechia and Ukraine are expected to boost cooperation in the military tech sphere, including the production of ammunition, small arms, as well as drones, electronic warfare, and heavy equipment.
The two countries plan to set up joint enterprises and continue annual training of up to 4,000 Ukrainian military personnel, according to the agreement.