Supporters of Taiwanese President Ma Ying-jeou are celebrating in the capital of Taipei and across the island.

The incumbent president claimed victory in Saturday's vote, telling throngs of supporters gathered at his election headquarters, “We have won,” after edging out opposition leader Tsai Ing-wen.

President Ma also told supporters there will be smoother ties with China during his next term, saying “relations will be more peaceful, with greater mutual trust and the chance of conflict will be less.”

With more than 90 percent of the ballots counted, Mr. Ma had 51 percent of the vote, compared to about 46 percent for Ms. Tsai.

Ms. Tsai conceded defeat and apologized to supporters at her Democratic Progressive Party headquarters. She urged President Ma to listen to all the Taiwanese people and “use his heart to lead.”

Ms. Tsai, who was attempting to become Taiwan's first female leader, also announced she was stepping down as party leader.

The election was being watched carefully in Beijing and in Washington.

U.S. President Barack Obama congratulated Mr. Ma on the victory, saying that improved relations between Taiwan and China, “are of profound importance” to the United States.

The U.S. is obliged by law to support Taiwan in the event of any hostilities with China. Beijing considers Taiwan a breakaway Chinese province and has threatened to use military force in the event of a declaration of independence.

Taiwan broke away from the mainland in 1949 at the end of the Chinese civil war in which Mao Zedong's communists defeated the nationalists under Chiang Kai-shek.