BUCHAREST: Pro-EU centrist Nicusor Dan on Monday will take the oath of office to become Romania’s president, having pledged to stand against “isolationism and Russian influence”.A week ago, Dan won a tense election rerun seen as key for the direction of the Nato and EU member country of 19 million people that borders war-torn Ukraine.The vote came five months after Romania’s constitutional court, in a shock move, scrapped a presidential ballot over allegations of Russian interference and the massive social media promotion of the far-right frontrunner, who was not allowed to stand again.Although EU critic and nationalist George Simion easily topped the first round of voting, Dan took victory in the second round run-off.Dan, 55, is scheduled to take the oath of office in parliament at noon (0900 GMT).The former mayor of Bucharest will then meet interim president Ilie Bolojan — who has been tipped as a possible prime minister.Dan, who has vowed to bring a “new chapter” to Romania, travelled to Warsaw on Sunday to support pro-EU Mayor Rafal Trzaskowski, who hopes to win Sunday’s race for the Polish presidency.“We won the Romanian presidential elections. People rejected isolationism and Russian influence,” Dan told thousands of people at a Trzaskowski rally. ‘Will resist’ Tensions remain high in Romania with authorities on alert after calls to protest on Monday by hundreds of TikTok users.“We will resist!” Simion, 38, wrote on Facebook on Sunday, although he specified that he would not be protesting on Monday.Romania’s constitutional court on Thursday validated the election results, after rejecting an appeal by Simion to cancel the vote.Simion alleges that there was foreign interference, including by France, and slammed the court’s decision as a “coup d’etat”.Simion comfortably topped the first-round ballot on May 4, campaigning against the EU’s “absurd policies” and vowing to cut aid to Ukraine.But Dan won almost 54 percent of the run-off vote.Romania’s president has significant sway in foreign policy — including representing the country at NATO and EU summits — and appoints key posts, such as the prime minister.Dan, a mathematics prodigy who has promised to fight corruption for an “honest” Romania, has said he would speak to all four pro-Western parliamentary parties about “not only the appointment of the prime minister, but also the outline of the government’s programme”, including justice reforms.Romanians are struggling with high inflation in the EU’s most indebted country.Dan, who became mayor of Bucharest in 2020 and is known for his reserved nature, has voiced support for Ukraine and vowed to keep Romania on its “pro-Western” path.