Afghan officials were treated to a surprise visit by the acting US Secretary of Defense, Patrick Shanahan, who arrived unannounced, apparently to discuss peace talks and the prospects for American military presence in the region.

Shanahan was appointed as acting president of Pentagon in December after Trump forced Defense Secretary James Mattis to leave his post early.

That included "achieving a political settlement to the war that ensures Afghanistan is never again used as a safe haven from which terrorists can plan and launch terrorist attacks against the United States, our interests and our allies", Robertson said. Some U.S. forces also carry out counter-terrorism operations.

The Taliban has refused to meet with the Afghan government calling it a "puppet" of the US.

He said: 'The Afghans have to decide what Afghanistan looks like in the future.

Shanahan's inaugural overseas trip as acting defense secretary comes as he seeks to prove his foreign policy credentials and establish a more public profile after 1 ½ years as deputy defense secretary under Mattis.

Speaking at the U.S. Institute of Peace in Washington on Friday, Khalilzad said Trump had been clear about his desire to end what he characterized as "endless wars".

"The U.S. military has strong security interests in the region".

He said the aim of his trip was to get an understanding of the situation on the ground from commanders and then brief Trump on his findings.

USA officials, led by chief negotiator Zalmay Khalilzad, have held several rounds of talks with the Taliban in Qatar and other countries in the region in the past eight months, in what is widely seen as the most serious bid yet for peace in Afghanistan since the Taliban were ousted by U.S. troops and US-backed Afghan forces in late 2001.

Both sides hailed progress after the latest round last month, although significant obstacles remain.

Votel noted that the Taliban are still capable of inflicting significant casualties on Afghan government forces.

The next round of talks is due on Feb 25 in Qatar where the Taliban has its political office. He said the U.S.is not seeking permanent military bases in Afghanistan and will leave if Kabul does not want US troops there, provided that there is no threat to USA national security from Afghanistan, particularly from terrorist groups.

Shanahan described Khalilzad as the "quarterback" of the American effort in Afghanistan but said the Pentagon would also play an important role in the peace effort. Shanahan had been Mattis' No. 2. "It's not about the US, it is about Afghanistan". Over the past few weeks, a USA delegation has been engaged in talks with the Afghan officials trying to prepare for a United States pullout.

"Of course it has given leverage to the Taliban, there is no question about that", the official told Reuters.

Shanahan also said he has no instructions from the White House to reduce the troop level in Afghanistan from the current 14,000. Earlier in the day, he visited an Afghan commando training site and received an update on the war from Gen. Austin "Scott" Miller, the commander of US and North Atlantic Treaty Organisation forces in Afghanistan.

"I think the presence we want in Afghanistan is what assures our homeland defence and supports regional stability".

Khalizad, who was appointed to his current post in September, said although he and the Taliban have made progress on the issue of a USA troop withdrawal, that is just one among many issues and none has been fully resolved.

However, the Taliban have put out contradictory information on what timeline the United States had agreed to in any potential withdrawal.