A knife-edge margin of 50.09% voted "yes" in Moldova's pivotal referendum on joining the European Union, partial results showed on Monday, after President Maia Sandu said Sunday's twin votes had been marred by "unprecedented" outside interference.

Moldovans were evenly split on Monday amid final counting in a geopolitically momentous referendum on European Union accession with 50.08% in favor and 49.92% against, electoral authorities said.

The European Union has condemned Russia's attempts to sway the outcome of the presidential election and the referendum on Moldova's European accession, promising to continue to support the country's democratic progress.