Editor's note: This story is being updated.
Lithuanian President Gitanas Nauseda, Latvian Prime Minister Evika Silina, and Czech Senate President Milos Vystrcil arrived in Kyiv on Sept. 11 ahead of the Crimean Platform summit.
More leaders are expected to visit Ukraine later this day as the country is holding the fourth Crimean Platform, an international consultation and coordination format aimed at ensuring the liberation of the peninsula from Russian occupation.
"Bringing military and economic support for (Ukraine) is crucial to defend its sovereignty and territorial integrity," Nauseda said.
The Baltic countries and the Czech Republic have been among Ukraine's staunchest supporters since the outbreak of the all-out war, providing the country with military aid and other support.
U.S. Secretary of State Antony Blinken and U.K. Foreign Secretary David Lammy will also visit Ukraine on a joint visit on Sept. 11. The two are expected to meet President Volodymyr Zelensky.
Their arrival comes amid mounting calls for the Biden administration to lift restrictions on long-range strikes deep inside Russia to allow Ukraine to better respond to Russian attacks.
Western countries have largely allowed Ukraine to use their arms in the Kursk Oblast incursion, but the U.S. and the U.K. have maintained their restrictions on the use of long-range arms like ATACMS or Storm Shadow.
Ukraine has reportedly used these long-range missiles to hit Russian military targets in Crimea, a sovereign Ukrainian territory illegally occupied by Russia.