"On behalf of the people of the United States, I extend my warmest congratulations to you and the people of Ukraine as you celebrate the 25th anniversary of your nation's independence on August 24. This day is particularly important in light of the threats posed to Ukraine's sovereignty and territorial integrity as a result of Russia's continued aggression in eastern Ukraine and its occupation and attempted annexation of Crimea," Barack Obama emphasized, Poroshenko's press service reported.

"I wish to assure you that the United States remains resolute in our commitment to stand with Ukraine as you confront Russian aggression," the U.S. president noted.

Read alsoFrench President congratulates Ukraine on Independence Day, calling it 'key actor' on global scene"As you celebrate your independence, I also wish to applaud the considerable strides you have taken to fight corruption, strengthen the rule of law, and lay the foundation for economic growth," he highlighted.

"I assure you that the United States will continue to support you as you work towards a more peaceful, prosperous European future for all Ukrainians," Obama said.