BRUSSELS (AP) — The European Union has completed an association deal with Ukraine which should boost trade between the two and keep the eastern European nation firmly linked to the EU.

After a long ratification process held up by a referendum in the Netherlands, the 28-nation EU said Tuesday the economic and political agreement should kick in on Sept. 1. The agreement comes on the eve of an EU-Ukraine summit in Kiev.

Ukraine was torn for years whether to align itself with Russia or the EU, but a fundamental change came when Russia invaded Ukraine’s Crimea peninsula three years ago. Fighting has continued in eastern Ukraine since then between Russian-based separatists and government forces.