President Obama on Saturday called Afghanistan's presidential election another important milestone in that country’s march toward democracy and praised the millions of Afghans who participated in the “historic” voting.

Obama said the Afghan people are taking full responsibility for their country as the United States and its allies gradually withdraw their forces.

Turnout in some places Saturday was so high that polling places ran out of ballots. There were few reports of disruption or violence at polling stations.

Partial results to choose a successor to President Hamid Karzai are expected Sunday.

“On behalf of the American people, I congratulate the millions of Afghans who enthusiastically participated in today's historic elections, which promise to usher in the first democratic transfer of power in Afghanistan's history and which represent another important milestone in Afghans taking full responsibility for their country,” Obama said.

He also paid tribute to the Americans -- military and civilian -- who sacrificed so Afghan people could “take responsibility for their own future.” And he commended the Afghan security forces and elections officials and noted the “spirited and positive debate among candidates and their supporters in the run-up to the election.”

Secretary of State John Kerry said: “The United States remains ready to work with the next president of Afghanistan. We will continue to stand with the people of Afghanistan as they work to build a democratic future.”

The Associated Press contributed to this report.