President Barack Obama in a Christmas Day speech to US troops stationed in Hawaii hailed their "extraordinary dedication and sacrifices," as NATO prepares to wrap up its combat mission in Afghanistan.

After a morning of exchanging gifts with family members during their annual year-end vacation in his birth state, the president and First Lady Michelle Obama paid a visit late Thursday to a Marine Corps base in Hawaii.

As service members and their families tucked into a dinner of lobster, turkey, green beans, yams and other traditional Christmas Day fare, the president took the microphone to thank them for "extraordinary service" that he said has allowed the United States to hand responsibility for security to Afghan forces.

"We've been in continuous war now for over 13 years. Next week we will be ending our combat mission in Afghanistan," Obama told the crowd, to cheers and applause.

"Because of the extraordinary service of the men and women in the armed forces, Afghanistan has a chance to rebuild its own country. We are safer. It's not going to be a source of terrorist attacks again," he said.

NATO's combat mission ends on December 31, although some troops will remain to support the Afghan army and police who have taken on responsibility for suppressing worsening Islamist violence nationwide.

Flags were lowered at Kabul airport earlier this month as the US-led NATO force in Afghanistan marked the closure of its combat command center.

There are concerns however about Afghanistan's ability to maintain security as the Afghan Taliban steps up attacks.

A follow-up mission of about 12,500 US-led NATO troops will stay on to train and support Afghan security forces.

Even as the main military mission in Afghanistan winds down, "we still have some very difficult missions around the world, including in Iraq," the president told the marines.

The US military will still play a key role stanching crises around the world, he said.

"We still have folks in Afghanistan helping the Afghan security forces. We have people helping to deal with Ebola in Africa and obviously we have folks stationed all around the world," said Obama.

"But the world is better, it's safer, it's more peaceful, it's more prosperous and our homeland is protected because of you and the sacrifices each and every day," he told the troops, praising "the extraordinary dedication and sacrifices you all make."