Former U.S. special representative for Afghanistan Zalmay Khalilzad has called for stronger U.S.-Afghanistan relations, saying improved ties are essential to bringing Afghanistan back into the international community while urging both Washington and Kabul to address key outstanding issues.

Speaking in an interview with The National of the United Arab Emirates, Khalilzad said Afghanistan should first address U.S. concerns over American citizens believed to be detained or missing in the country.

He said there are three major obstacles to improving relations between Washington and Kabul.

The first is the fate of three American citizens whom he said are either being held in Afghanistan or have gone missing. Khalilzad said Washington needs clearer information about their cases and a mechanism to deal with similar issues.

The second challenge, he said, is continued U.S. disappointment and frustration over the outcome of its 20-year involvement in Afghanistan. He said addressing those concerns would take time and require both sides to confront the realities of the past as well as future U.S. interests.

The third challenge is IEA policies, particularly restrictions on girls’ education. Khalilzad described the restrictions as a major symbol of the issues the United States had sought to address during its two decades in Afghanistan, calling the policy morally wrong and socially short-sighted.

At the same time, Khalilzad urged Washington to expand its engagement with Afghanistan, warning that a limited U.S. presence could create a strategic vacuum.

He said reduced engagement could allow U.S. rivals to increase their influence in Afghanistan, create opportunities for terrorist groups and further harm ordinary Afghans who have already endured decades of conflict.

“Turning our backs on Afghanistan and limiting engagement to a minimum is, at best, a mistake,” Khalilzad said, according to his comments published by The National.

Assessing Afghanistan five years after the IEA returned to power, Khalilzad said developments had differed from what many had expected.

He said concerns that Afghanistan would become a much greater source of terrorism, face worsening internal security or experience economic collapse after the end of large-scale foreign assistance had not fully materialized.

Khalilzad also said the IEA had demonstrated greater-than-expected capabilities in areas including infrastructure development, agriculture and regional diplomacy, particularly in its relations with Central Asian countries such as Uzbekistan.

However, he said the deterioration in Afghanistan-Pakistan relations had been unexpected. He criticized what he described as Pakistan’s increasingly hostile approach and its return to policies of supporting opponents of the Afghan authorities.

Khalilzad also identified Afghanistan’s prolonged political transition as a major challenge, saying there is still no clear roadmap for establishing a permanent constitution or political system.

His comments come as Afghanistan marks five years since the IEA took control of Kabul.