A vote seen as a test of the power of populist nationalism in Europe was too close to call, with exit polls putting the two contenders neck and neck.

Conservative Karol Nawrocki narrowly won Poland's presidential runoff election, beating Warsaw's liberal mayor, according to the final vote count. Nawrocki was backed by President Trump.

Poland is set to hold a presidential runoff election in which a right-wing nationalist and a pro-European liberal are running neck-and neck.