Ukraine president signs amendment on NATO, EU membership Ukraine's president has signed constitutional amendments committing to join NATO and the European Union

KIEV, Ukraine -- Ukraine's president on Tuesday signed a constitutional amendment committing to join NATO and the European Union, acknowledging that the nation still has a long way to go to meet the membership criteria.

Speaking in parliament, Petro Poroshenko said he sees securing Ukraine's membership in the EU and NATO as his "strategic mission."

Poroshenko, who is running for a second five-year term in the March 31 election, told parliament that he aims to make a formal bid to join the EU by 2023 and also negotiate a detailed action plan for joining NATO.

He acknowledged, however, that Ukraine needs to go a "long way" to "do its homework" on meeting the criteria of joining both the EU and NATO.

Poroshenko criticized those Ukrainian politicians who say that Ukraine shouldn't join any blocs and argued that the nation's bloc-free status has encouraged Russian "aggression."

European Council President Donald Tusk addressed the parliament in Ukrainian, declaring that "there is no Europe without Ukraine." He pledged that the EU would never acknowledge Russia's 2014 annexation of Ukraine's Crimean Peninsula and would keep its sanctions against Moscow.