STThe Ford administration quietly stopped all military assistance to Indonesia from December, 1975, until June, 1976, because of reports of barbarity by Indonesian troops in East Timor, the State Department revealed yesterday.

The unannounced and unleaked temporary sanction against Indonesia contrasts with the publicity proclaimed Carter administration cutoffs of aid to Uruguay Argentina and Ethiopia which have aroused controversy here and abroad.

Deputy Assistant Secretary of State Robert B. Oakley told a House subcommittee that the secret aid cutoff coincided with the period in which most killings in East Timor took place.

Oakley said that casualty figures ranging up to hundreds of thousands in East Timor reported by the press "are greatly exaggerated." He said "we would judge the total casualties were under 10,000."

East Timor was a Portuguese colony until it was given independence following Portugal's 1974 revolution. Indonesia moved to annex the formerly Portuguese half of Timor after a leftist government came to power there which Indonesia saw as a threat to its half of the remote island.

Oakley told Rep. Lester L. Wolff's Subcommittee on Asian and Pacific Affairs that the Ford administration resumed military assistance and recognized Indonesia's annexation and that the Carter administration is following that policy.

As a result, from the U.S. standpoint, if Indonesia uses any of the $58 million in proposed U.S. military assistance for fiscal 1978 in East Timor, it is defending its own territory.

On another subject, Wolff asked Michael Adler, acting assistant administration of the Agency for International Development, about reports of unwarranted sterilization programs in Burma and Thailand that may have resulted in eliminating the small Akha tribe, which presently consists of about 600 people.

Wolff said the effective labor force of the Akha people will cease to exist in 18 to 27 years as a results of an AID-financed program. He asked if this wasn't almost genocide.

"Yes, you could almost say that," Adler replied. Adler promised that the subcommittee would be given the full report fo an AID team now investigating the sterilization programs.