By Idrees Ali
KABUL (Reuters) - The United States will "remain committed" to Afghanistan, U.S. Defense Secretary Ash Carter said on Friday, amid questions about what President-elect Donald Trump's foreign policy will mean for the country as it faces a renewed Taliban insurgency.
Carter arrived in the Afghan capital earlier on an unannounced visit and met U.S. troops and Afghan President Ashraf Ghani.
"America is, and will remain, committed to a sovereign and secure Afghanistan," Carter told a news conference with Ghani.
Trump has given few details of his foreign policy plans, with surprisingly few specifics on Afghanistan, where nearly 10,000 U.S. troops remain more than 15 years after the Islamist Taliban were toppled by U.S.-backed Afghan forces.
Afghanistan was barely mentioned during a bitterly fought election campaign, which largely focused on domestic issues, between Republican Trump and his Democratic rival, former secretary of state Hillary Clinton.
Trump, however has said the United States should stop carrying out "nation building".
Ghani and Trump spoke by telephone last week and the Trump transition team said in a statement they discussed the "terrorism threats facing both countries". [ nW1N1D90GK]
Speaking with reporters at Bagram air base north of Kabul later on Friday, General John Nicholson, the commander of U.S. and international forces in Afghanistan, said it was important for the United States to remain committed in Afghanistan.
"Our policy of having an enduring counterterrorism effort alongside of our Afghan partners is, in my view, very sound and something we need to continue," Nicholson said.
Leaders of five out of the 20 designated militant organizations in the Afghanistan-Pakistan region had been killed and Islamic State had lost two-thirds of its territory, something that needed to continue in future, he said.
Carter said the Trump transition team had not asked to speak to Nicholson, but he would be made available if requested.
One of the most important questions facing Trump on Afghanistan, former officials and experts say, is how many U.S. troops will stay on there.
Acknowledging that Afghan security remained precarious and Taliban forces had gained ground in some places, President Barack Obama shelved plans to cut the U.S. presence almost in half by year's end, opting instead to keep 8,400 troops there through to the end of his presidency in January.
Ghani thanked Carter for the U.S. military contribution and its sacrifices in the conflict.
James Dobbins, a former U.S. special envoy for Afghanistan, said Afghanistan would not figure highly for Trump, given the fight against Islamic State militants in Syria and Iraq.
This, Dobbins said, was likely to mean that the number of U.S. troops in Afghanistan would remain unchanged, at least in the short term.
Trump will inherit a challenging security situation in Afghanistan.
A number of provincial capitals have been under pressure from the Taliban while Afghan forces have been suffering high casualty rates, with more than 5,500 killed in the first eight months of 2016.
(Additional reporting by Hamid Shalizi; Editing by Paul Tait, Robert Birsel)