MINSK, Belarus (AP) — Ukraine’s president says the country needs to amend its constitution to make NATO membership its long-term goal.

President Petro Poroshenko said Thursday that Ukrainians are finally convinced of the benefits of the alliance with NATO and said the Ukrainian army will meet the criteria for NATO membership by 2020.

Ukraine abruptly changed its pro-Russian stance following the overthrow of the pro-Kremlin government in 2014 and Russia’s annexation of Crimea a month later. One of the arguments that Russia used to justify the annexation was fears that Ukraine would invite NATO troops to Crimea’s strategic Black Sea port of Sevastopol.

Following Poroshenko’s speech, the Ukrainian parliament voted to appeal to the Constitutional Court to review the amendments.