Relations between Pakistan and the United States declined after U.S. Navy SEALs last May and killed al-Qaida leader Osama bin Laden at a compound in Pakistan.
Islamabad closed its border for NATO convoys entering Afghanistan, leaving hundreds of supply trucks idled along the border.
Pakistani Prime Minister Syed Yousuf Raza Gilani told the BBC in a weekend interview that the blockade would remain in place at least through the end of the month. The airspace, he added, might be closed to U.S. forces in response to last month's strikes.
"There is a credibility gap, we are working together and still we don't trust each other," the Pakistani prime minister was quoted as saying.
Pakistan boycotted a conference on Afghanistan last week in Bonn, Germany, in response to the airstrike.
Zalmay Khalilzad, former U.S. envoy to Afghanistan, told Radio Free Europe/Radio Liberty that, without Pakistan, the international effort to stabilize Afghanistan could "take much longer."