The election results could reshape the instructions of pro-EU and NATO members bordering war-torn Ukraine.
Romanians have begun voting in the tense presidential election, which brings a pro-Trump nationalist to those who oppose Ukraine's opposition to military aid at the pro-European Union centre.
The poll opened at 7 a.m. on Sunday (04:00 GMT) and will be closed in the second round of elections at 9 p.m. (18:00 GMT), which will affect Romania's geopolitical direction.
George Simion, a 38-year-old hard nationalist, opposed military aid to neighboring Ukraine and criticized EU leadership, decisively swept the first round of the presidential election, triggering the collapse of the pro-Western coalition government. This has led to a large amount of capital outflows.
Romania's Supreme Court canceled its first round of results in December for allegations of Russian interference. The court also disqualified the leading nationalist candidate, Calin Georgescu, to make room for Simion, a self-proclaimed fan of U.S. President Donald Trump.
Nicusor Dan, the Mayor of Bucharest, the 55-year-old Centre, who is competing with Simion, who promises to cut corruption and unwaveringly support the EU and NATO. He said Romania's support for Ukraine is crucial to its growing security threat to Russia.
A poll on Friday showed that Dan was a slightly ahead for the first time since the first round of a tense race, which would depend on turnout and a massive Romanian diaspora.
Al Jazeera's Sonia Gallego said in a report in the capital Bucharest that the election was considered a battle between nationalist populism and centrists.
"The reality is that Romania is a member of the EU and NATO, sharing borders with war-torn Ukraine (the longest among EU members). This also makes it one of the most vulnerable people in the group," she said.
Some analysts also warn that online disinformation is once again prevalent before Sunday’s vote.
"We have to study what's going on online. There, we've seen a lot of misinformation," political analyst Elena Calistru told Al Jazeera.
"We've seen a lot of … coordinated untrue behavior. We've seen a lot of foreign intervention in the election," she said.
The president of the country has considerable power, especially the National Defense Commission responsible for deciding military aid. He will also monitor foreign policy and have the power to veto the EU vote that requires consistency.
Daniela Plesa, 62, told AFP in Bucharest on Friday that she hoped the president "to promote the interests of the country" and complained about "the need and demand of the EU."
Andreea Nicolescu, 30, who works in advertising, said she hopes to be "a little calmer" and "pro-European president".
Thousands of rallies ahead of the election demanded that the country maintain its pro-EU stance.
Other protests, which have attracted thousands, have also condemned the decision to repeal last year's vote and banned far-right candidate Georgescu.
The Trump administration criticized the cancellation, and Sinion said his prime minister's draft pick would be Georgescu, who favors nationalization and openness to Russia.
The Romanian vote, on the day Poland voted in the first round of the presidential election, is expected to be led by Pola Warsaw Mayor Rafal Trzaskowski and conservative historian Karol Nawrocki.
The victory of Simion and/or Trzaskowski will expand a group of European-doubted leaders who already include the prime ministers of Hungary and Slovakia, while a political shift in Central Europe could widen the EU’s rift.