A senior US senator urged Pakistan to crack down on the Al-Qaida-linked Haqqani insurgent network, which operates on both sides of the country's border with Afghanistan.
Sen Carl Levin, chairman of the Armed Services Committee, said he does not think the Haqqani network will ever make peace and he vowed to push to include the group on the US terrorist blacklist.
The senator praised Pakistan for its help in fighting terrorism and for taking on other militants such as the Pakistan Taliban, but he said the country's reluctance to push into the North Waziristan area run by the Haqqanis is hurting the war effort in Afghanistan.
"They are not following through and have not followed through by going after one of the truly great threats that face us here in Afghanistan, which is the coming into Afghanistan from Pakistan of Haqqani fighters," the Democrat from Michigan told reporters in Kabul on Sunday at the end of his two-day visit.
The Haqqani network, which mainly focuses on attacking targets in Afghanistan, is suspected of maintaining ties to Pakistan's powerful military intelligence agency.
The Pakistani government has denied news reports that it has reached out to the Haqqani network to secure its participation in talks with the Afghan government.