Pakistan has called on the United States to agree upon ‘clear terms of engagement’ in the fight against militants.During a meeting in Islamabad Monday, President Asif Ali Zardari told the U.S. special representative to Pakistan and Afghanistan, Marc Grossman, the terms should be clearly defined and specified so that any dispute could be settled amicably through the available institutions.Mr. Zardari said that a long-term, sustainable relationship with the U.S. should be based on mutual interest, trust and respect.The two officials also discussed bilateral ties, regional security and the situation in neighboring Afghanistan, with the Pakistani president saying that a peaceful and stable Afghanistan is in the interest of peace and stability in Pakistan.The remarks come at a low point in relations between Pakistan and the United States. Pakistan sharply criticized the covert U.S. raid on May 2 that killed Osama bin Laden in the Pakistani city of Abbottabad as a violation of its sovereignty. On Sunday, Pakistani officials said the government had imposed travel restrictions on American diplomats living in Pakistan.The U.S. recently suspended about one-third of its $2.7 billion annual defense aid to Pakistan in response to Pakistan's decision to expel American military trainers and put limits on visas for U.S. personnel.