George Simion, a nationalist and vocal supporter of U.S. President Donald Trump, has won Romania’s first-round presidential election after capitalizing on widespread anti-establishment sentiment.

A George Simion victory could isolate Romania, erode private investment and destabilise NATO's eastern flank, where Ukraine is fighting a three-year-old Russian invasion, political observers say.

Romania's frontrunner for the May 18 presidential elections, George Simion, announced his plans, which include bringing radical far-right politician Călin Georgescu as prime minister and forming a parliamentary majority around his Alliance for the Union of Romanians (AUR) party,