Voters in Turkey returned to the polls Sunday to decide whether the country's longtime leader stretches his increasingly authoritarian rule into a third decade or is unseated by a challenger.

After an inconclusive round one, Sunday's vote should decide whether citizens still want President Recep Tayyip Erdogan in charge for another five-year term, and he could have an edge to win.

Neither longtime Turkish leader Recep Tayyip Erdogan nor his main challenger Kemal Kilicdaroglu were able to win more than 50% of the vote. That means Turkey is heading for a runoff on May 28.

Voters in Turkey took to the polls on Sunday for landmark elections that are expected to be close and could be the biggest challenge Turkish President Erdogan faces in his two decades in power.

President Biden reassured his NATO allies that the U.S. has their backs, and said he was gratified that the alliance will now also focus on challenges from China, climate change and cyberattacks.

President Biden will be in Europe for eight days, first meeting with allies and partners at the G7 and NATO summits. And then, he'll square off with Russian President Vladimir Putin in Geneva.

The increased friction follows the beheading of a French teacher after he showed his class caricatures of the Prophet Mohammad. The two countries have sharp foreign policy differences.