Turkey's Recep Tayyip Erdogan on Saturday promised to serve impartially, after winning a historic runoff election to extend his two-decade rule.
Turkey's transformative but divisive leader won the May 28 runoff against a powerful opposition coalition, despite an economic crisis and anger over a February earthquake that killed more than 50,000 people.
Erdogan won 52.18 percent of the vote while his secular rival Kemal Kilicdaroglu scored 47.82 percent, official results show.
"As president, I swear upon my honour and integrity, before the great Turkish nation ... to work with all my power to protect the existence and independence of the state ... and to fulfil my duty impartially," Erdogan said in parliament after a ceremony outside the building where he saluted soldiers under pouring rain.
Supporters in parliament gave Erdogan a minute-long standing ovation after his swearing in, while some opposition lawmakers refused to stand up.
In his oath, Erdogan also promised not to deviate from the rule of law and the secular principles of the republic founded by Mustafa Kemal Ataturk 100 years ago.
Turkey's longest-serving leader now faces significant immediate challenges in his third term, including the slowing economy and tensions with the West.
"From a geopolitical point of view, the election will reinforce Turkey's recent pursuit of an independent foreign policy," said Matt Gertken, chief geopolitical strategist at BCA Research.
"This policy aims to extract maximum economic and strategic benefits from eastern and autocratic states while still preventing a permanent rupture in relations with western democracies," he said.
"Tensions with the West will likely increase again," Gertken added. (AFP)