A meeting between U.S. and Russian Presidents Donald Trump and Vladimir Putin, due to be held in Helsinki next week, will confirm that Ukraine is at the forefront of European and transatlantic politics, Ukrainian President Petro Poroshenko has written in an article published on the website of British newspaper Financial Times.

This "Ukrainian Week' will send a powerful message that will be heard in Brussels and abroad - the most important thing in Helsinki. Based on our agreed approach to do nothing about Ukraine without Ukraine, I wish Mr. Trump success in his attempts to get Putin back on track. Knowing the Russian president, I can argue that he wants our defeat, but this is not an option, and this will never happen, Poroshenko wrote.

He also noted that the meeting between Trump and Putin would be held on the 28th anniversary of the proclamation of state sovereignty by the Ukrainian parliament.

Poroshenko said that problems facing Ukraine are now huge, but now is not the time to ease pressure on Russia.

To do so would be recognition of weakness. Instead we must make it clear that the values and principles of the free world will not be compromised... In Brussels this week we will make it clear that the price for Russia for its aggression will grow until the Minsk agreements are implemented and the occupation of Crimea and Donbas ends. It's time for concrete actions, Poroshenko wrote.

Trump and Putin are expected to meet in the Finnish capital, Helsinki, on July 16.