WASHINGTON, April 1— United States military planes will begin evacuating dependents of American officials and private United States citizens from East Pakistan tomorrow, the State Department announced today.

It was understood that Britain would also begin airlifting British subjects from the area, which has been torn by civil strife for a week.

As the United States made its decision to move, Senator Edward M. Kennedy charged that the Nixon Administration was in effect suppressing re ports from East Pakistan of “indiscriminate” killing, continuing fighting and a mounting threat of famine.

Official sources said that American C‐130 transport planes would fly in from Utaphao air base, Thailand, and would take the Americans from Dacca in East Pakistan to Bangkok, Thailand. Smaller air planes may lift some out from the Chittagong airport. It had been hoped that chartered civilian aircraft could be used, officials said, to reduce the air of emergency in deference to the Pakistani Government, which has announced that calm is rapidly returning to East Pakistan.

Officials said that current plans called for only one air plane to fly in each day to soften any hint of emergency.

“This is not an emergency evacuation,” the State Department spokesman insisted. “This is a temporary reduction in number of Americans in East Pakistan.”

He conceded, nonetheless, that although the evacuation of private American citizens would be optional, dependents of United States officials would have to leave.

Civilian airlines refused to risk landing at Dacca, where Pakistani troops are said to guard both the airport and the control tower. Experienced Bengali air controllers have fled, sources here say. United States military planes, which have had their own ladders and starting equipment therefore had to be used.

Charles W. Bray, 3d, the State Department spokesman, said that the United States intended to leave a substantial number of the 80 American officials in East Pakistan at the consulate general. Otherwise, he intimated, virtually all the 705 Americans in the area would be flown out.

While reluctant to go into details—again in deference to White House orders not to inflame Pakistani opinion — Mr. Bray indicated that disruption of mail, telephone and other community services, plus the closing of schools, made it impossible for the American com munity to lead a normal life.

Source of Report Unknown

Senator Kennedy's statement did not identify the source of the reports reaching his Senate refugee subcommittee. The re ports charge systematic execution of dissident Bengali political leaders and students by the Pakistani armed forces.

Staff aides said, however, that duplicates of cablegrams from Archer K. Blood, the United States consul general at Dacca, were circulating widely throughout the State and De fense Departments, the Agency for International Development, the Central Intelligence Agency and other branches of the Federal bureaucracy.

They indicated that officials concerned over conditions in East Pakistan and offended by the White House orders for tight secrecy had furnished the gist of the reports to Senators and Representatives.

Senator Fred R. Harris, Democrat of Oklahoma, called on the Nixon Administration to cut off all military and economic aid to Pakistan until it was clear whether there had been a mass slaughter of East Pakistanis.

Officials said that economic aid to Pakistan was running at $100‐million yearly. Military aid that began in 1954 was cut off in 1965 after the Indian Pakistani war. Its total at that time, they said, was approximately $750‐million.

Academic leaders at Harvard, who declined to be identified, said that several of their number with experience in Pakistan had telephoned Henry A. Kissinger, President Nixon's adviser on national security, to urge United States pressure on Pakistan to restrain her troops, restore civilian rule and permit the delivery of food, medical supplies and other relief goods.

They declined to describe Mr. Kissinger's response.