President Obama made a surprise visit to Afghanistan on Sunday as his administration plans to end the nation's longest war this year, and faces intense criticism over the medical treatment of American veterans.
"I'm here on a single mission, and that is to thank you for your extraordinary service," Obama told a rally of some of the 32,800 American servicemembers serving in Afghanistan, many of them making their last tour of duty.
After making a secret overnight flight from Washington, D.C., Obama told the troops at Bagram Air Field that the United States is at "a pivotal moment," and that Afghan forces will compete their takeover of security responsibilities by the end of this year.
"Our combat mission will be over," the president said.
During a briefing with military commanders, Obama said he would soon announce troops levels for a post-2014 residual force to be left in Afghanistan to keep training local security forces and conduct counterterrorism missions.
In addition to his speech and an on-site briefing from military commanders at Bagram Air Field, Obama also visited wounded troops at the base hospital.
Country music star Brad Paisley traveled with the president, and performed for troops at Bagram. As the presidential party landed, Paisley tweeted: "About to play a surprise concert for the troops in Afghanistan. God bless our military. Here we go."
The Memorial Day weekend visit comes as Obama plans to wind down the Afghanistan war by year's end, though officials want to leave what Obama called "a limited military presence" in Afghanistan beyond 2014. During his security briefing, Obama said he would make an announcement "fairly shortly" about residual troop levels.
While Afghanistan can remain "a very dangerous place," Obama lauded the troops for "progress" during the war that ranges from expanded economic development in the country to education for girls who had once been denied it.
Obama also said the U.S. has "decimated" the leadership of the al Qaeda terrorist organization that plotted the attacks of Sept. 11, 2001, including the death of leader Osama bin Laden.
The surprise trip also follows attacks over the treatment of veterans at Veterans Affairs hospitals, including reports that officials are trying to cover up evidence of long wait times and that some veterans have died while awaiting treatment.
In his weekend radio address, Obama said "we've seen again how much more our nation has to do to make sure all our veterans get the care they deserve," and the nation has a "sacred obligation" to follow through.
"Now that we've ended the war in Iraq, and as our war in Afghanistan ends as well, we have to work even harder as a nation to make sure all our veterans get the benefits and opportunities they've earned," Obama said. "They've done their duty, and they ask nothing more than that this country does ours — now and for decades to come."
The president is not scheduled to meet Sunday with Afghanistan President Hamid Karzai, with whom the president has had a difficult relationship. Afghanistan is in the midst of a run-off election to replace Karzai.
Air Force One landed at Bagram Air Field on Sunday night, local time, after a secret trip that began Saturday night.
A U.S.-led coalition first invaded Afghanistan in October of 2001, a month after the 9/11 attacks; Afghanistan had served as a safe harbor for the 9/11 plotters. In recent years, U.S. troops have battled insurgents seeking to regain control of the country, though Obama said the country is no longer a "safe haven" for terrorists.
This was Obama's fourth visit to Afghanistan, his first since the 2012 re-election year.
About 32,800 U.S. troops remain in Afghanistan, down from a high of 100,000 in mid-2010. At least 2,181 U.S. military servicemembers have died during the Afghan war, and thousands more have been wounded.
In his remarks to troops, Obama noted that during his tour of Bagram he saw a picture of the twin towers of the World Trade Center that were attacked in 2001. "So I know you don't forget," Obama said.
The plan to maintain a small force in Afghanistan depends on Karzai's soon-to-be-elected successor signing a bilateral security agreement that Karzai has refused to endorse.
Ben Rhodes, deputy national security adviser for strategic communications, said Obama had been looking for an opportunity to get back to Afghanistan, and this trip provided "an opportunity for the president to thank American troops and civilians for their service."
Rhodes said the administration is "making some decisions about the future of our commitment to Afghanistan," and the briefings with give Obama a chance to assess the security and political situation as Afghanistan holds new elections.
"It is important for him to come before he articulates a decision" about a residual force, Rhodes said.
Contributing: The Associated Press