The United States signed a historic deal with Taliban insurgents on Saturday that could pave the way toward a full withdrawal of foreign soldiers from Afghanistan over the next 14 months and represent a step toward ending the 18-year-war there. 

The deal was signed in the Qatari capital Doha by U.S. special envoy Zalmay Khalilzad and Taliban political chief Mullah Abdul Ghani Baradar. U.S. Secretary of State Mike Pompeo was on hand to witness the ceremony. 

U.S. Defense Secretary Mark Esper meanwhile traveled to Kabul on a visit that officials and experts said was aimed at reassuring the Afghan government about the United States' commitment to the country. 

After an initial reduction of troops to 8,600 within 135 days of Saturday's signing, the U.S. and its partners "will complete the withdrawal of their remaining forces from Afghanistan within 14 months... and will withdraw all their forces from remaining bases," Washington and Kabul said in a joint statement. 

The U.S. currently has between 12,000 and 13,000 troops in Afghanistan.

"Today is a monumental day for Afghanistan," the U.S. Embassy in Kabul said on Twitter. "It is about making peace and crafting a common brighter future. We stand with Afghanistan." 

For U.S President Donald Trump, the deal represents a chance to make good on his promise to bring U.S. troops home. 

Nevertheless, Esper warned that the U.S. "will not hesitate to nullify" its historic deal with the Taliban if the insurgents renege on their security guarantees and commitment to hold talks with the Afghan government. 

Hours before the deal, the Taliban ordered all its fighters in Afghanistan "to refrain from any kind of attack ... for the happiness of the nation." 

"The biggest thing is that we hope the U.S. remain committed to their promises during the negotiation and peace deal," said Zabiullah Mujahid, a spokesman for the hardline Islamist group. 

Mujahid said it was "irritating and provocative" that foreign military aircraft continued to fly over Taliban territory, but militia fighters were following the order to stand down.

The Taliban's sheltering of al-Qaeda was the main reason for the U.S. invasion of Afghanistan in 2001 following the 9/11 attacks. More than 100,000 Afghan civilians have been killed or wounded over the past decade, according to the United Nations. 

The U.S. and the Taliban will exchange thousands of prisoners ahead of intra-Afghan talks, the deal said. 

While the agreement paves the way for the United States to gradually pull out of its longest war, many expect that talks to come between the multiple Afghan sides will be far more complicated. 

The Taliban have until now dismissed Afghan President Ashraf Ghani's government as a U.S. puppet, while Kabul has been excluded from direct U.S.-Taliban talks. On the other hand, disputes between Ghani and his rival Abdullah Abdullah are also an obstacle to nationwide reconciliation and peace. 

Commenting on the agreement between the U.S. and the Taliban, Chinese Foreign Ministry spokesperson Zhao Lijian said on Monday that Beijing firmly supports the broad and inclusive peace and reconciliation process that is Afghan-led and Afghan-owned. 

"China believes foreign troops in Afghanistan should withdraw in an orderly and responsible manner to ensure a stable transition and avoid a security vacuum, which terrorist organizations may take advantage of to fester," he said at a regular press briefing.

(With input from Reuters, AFP)