The final result of Austria's presidential election was set to be announced by Monday evening, after Sunday's vote resulted in a dead heat between Green candidate Alexander Van der Bellen and his far-right rival Norbert Hofer.
Pollsters projected both contenders to win 50 per cent of the ballots, with the former Green party chief leading by fewer then 3,000 votes.
Absentee ballots that will be counted until Monday evening will decide whether Austria's president in the coming six years will be a Green pro-European Union economist, or a eurosceptic with an anti-immigration stance.
Faced with evenly split voters, the two candidates stressed the need to bridge political divisions among Austrians.
"The person who wins will have the duty to unite," Hofer said Sunday evening.
"After the election, people usually sit down and try to work together as well as possible, according to good Austrian tradition," Van der Bellen said.
Foreign Minister Sebastian Kurz called for the result of the election to be respected, irrespective of "what it looks like and whether one is happy with it."
"No matter how the election pans out, I will do everything to keep Austria as a responsible partner on the European level," he told journalists in Brussels, where he was attending a meeting of EU foreign ministers.
The far right has been gaining traction in Europe for months and concerns are rife that the Austrian election will be a harbinger of things to come in other parts of the European Union.
"It is worrying to see what is happening in many European countries, through populist gains whether it be [on] the extreme right or the extreme left," Belgian Foreign Minister Didier Reynders said as he arrived for the EU meeting in Brussels.
He attributed the trend to sensitive subjects such as migration and security, which are currently at the top of the European agenda. But other ministers said that pro-European forces in the EU may also have fallen short.
"We ... mayde did not always defend Europe with the right arguments," said Luxembourg Foreign Minister Jean Asselborn, who expressed the hope that the "Europe-minded" presidential candidate will win in Austria.
"People are dissatisfied with the traditional, standard political parties," Slovak Foreign Minister Miroslav Lajcak added. "I really believe it's time for us to reflect upon it, because we must be doing something wrong."