Richard Holbrooke, the Special US Representative for Pakistan and Afghanistan, talked to Pakistan President Asif Ali Zardari and Prime Minister Yousuf Raza Gilani over phone and discussed with him the situation in the country.

The US Ambassador to Pakistan, Anne W Patterson, also spoke on Thursday to opposition leader Nawaz Sharif in Lahore. Admiral Mike Mullen, Chairman of the US Joint Chiefs of Staff, said he doesn't believe there is a "high probability right now" the crisis will prompt Pakistan military to intervene.

In an interview with PBS's Charlie Rose broadcast late on Thursday night, Mullen said his Pakistani counterpart Gen Ashfaq Kayani is "committed to a civilian government" and doesn't want to take over as his predecessor Pervez Musharraf did in 1999.

"The situation in Pakistan continues to deteriorate very, very slowly under a political leadership which is very challenged because of the totality of the crisis," Mullen said and added "officials are closely monitoring opposition protests" in Pakistan.

The official Associated Press of Pakistan reported from Islamabad that Zardari had a three-way teleconference with Patterson and Holbrooke.

"A host of issues of mutual interest to both Pakistan and the US came under discussion in the teleconference that lasted for about thirty minutes," President's spokesman Farhatullah Babar was quoted as saying.

State Department Robert Wood said: "Without going into a lot of detail, you know, (US) Ambassador (to Pakistan) Patterson and Ambassador Holbrooke have been talking to the Pakistani Government about this issue."

"Our Embassy (in Islamabad) has had conversations with other elements of Pakistani society about this," he said. The United States, he said, want to make sure that no violence takes place and that; all differences are resolved within the political construct of Pakistan’s constitution.