Doha conference, which was jointly hosted by Qatar and Germany, witnessed the attendance of Afghan government representatives for the first time but the three officials spoke in their personal capacity.
As the "selected group of Afghan activists and civil society figures" prepared to meet with the Taliban in Qatar, the terrorist group carried out a deadly auto bomb attack in central Afghanistan on Sunday, "casting a pall over talks meant to open the way for full [intra-Afghan] peace negotiations in the future", the Guardian notes.
Furthermore, he said what has been reached today may be only a first step to find an understanding between the conflicting parties.
"The Doha peace conference participants strongly supports the current peace talks in Doha and believe that an effective and positive outcome from the negotiations will be fruitful for Afghanistan", the resolution further said.
The framework the two sides agreed to has four pillars - USA withdrawal; the Taliban agreeing to prevent Afghanistan from becoming a terror safe haven; a permanent ceasefire; and intra-Afghan negotiations.
"They engaged in substantive discussion over the course of two days covering a wide range of issues of common concern to the Afghan people, including rights of women and minorities, a cease-fire, the withdrawal of foreign troops and combatants, and the political future of Afghanistan", Germany and Qatar said.
Khalilzad said USA and Taliban negotiators have also made progress on a cease-fire deal and discussed the conditions in which foreign forces will be reduced and eventually withdrawn from the country.
Koofi said the sides agreed to the wording of the document on July 8 after about 14 hours of "long and exhaustive" talks. The Taliban has refused to hold direct negotiations with the Afghan government until the USA announces a timetable for the withdrawal.
Around 70 delegates attended the gathering at a luxury hotel in Doha and the large meeting room erupted into applause after the statement had been read out.
Earlier too, the Taliban has refused to hold direct dialogues with the Afghanistan President Ashraf Ghani-led government until Washington announces its final timetable for troops' withdrawal from the region.
The seventh round of peace talks between the insurgent group and the USA negotiators is likely to be relaunch later on Tuesday.
Al Jazeera's Charlotte Bellis reports from Doha.
Khalilzad has described the latest round of U.S. -Taliban talks as the "most productive" ever, telling RFE/RL that "a lot of progress" has been made.
The US is not participating directly in the two-day Afghan summit, which is being attended by political heavyweights, government officials and at least six women.
Despite the violence, both the Taliban and USA have been positive about their engagement.