WASHINGTON, Feb. 11 (Xinhua) -- The U.S. Department of Defense said Monday that acting Secretary of Defense Patrick Shanahan paid an unannounced visit to Afghanistan, holding talks with President Ashraf Ghani and Afghan officials on a wide range of issues.

Shanahan met with Ghani, Afghanistan's chief executive Abdullah Abdullah and other officials, a Pentagon press release said.

The Pentagon acting chief said earlier that he had not received orders to begin to withdraw U.S. troops from Afghanistan.

Shanahan's trip was widely believed to serve to relieve Kabul's increasing concern about its exclusion from recent talks between the United States and the Afghan Taliban.

The Pentagon has reportedly stepped up airstrikes and special operations of raids in Afghanistan to the highest levels since 2014, aiming to give negotiators leverage in peace talks with the Taliban.

U.S. Special Representative for Afghan Reconciliation Zalmay Khalilzad said at an event in Washington on Feb. 8 that he expected a final deal could be reached before Afghanistan's presidential election in July.

Khalilzad had six days of consultations with the Afghan Taliban last month in Qatar. The U.S. envoy said significant progress on vital issues was made during the meetings.

However, Khalilzad pointed out "a number of issues left to work out," saying that an agreement "must include an intra-Afghan dialogue and comprehensive ceasefire."

Although the progress in Qatar was hopeful, analysts believed that reaching a final agreement is far from guaranteed, saying the Taliban still refuses to negotiate a political settlement with the Afghan government.

Another round of peace talks between the United States and the Taliban is tentatively set for Feb. 25, according to media reports.

Shanahan, a former Boeing executive, has been in charge of the Pentagon since Jan. 1. The trip to Afghanistan was also his first overseas visit as acting defense secretary.

There are about 14,000 U.S. troops currently deployed in Afghanistan, and Washington has reportedly planned to withdraw half of them.

The death toll of U.S. servicemen in Afghanistan has surpassed 2,400 since the United States invaded the Asian country in 2001.