The Bolivian military high command, which has accused the U.S. ambassador of interfering in this country's internal affairs, tonight called for a year's postponement of elections scheduled later this month.

Earlier today the high command was reported to have threatened President Ambassador Marvin Weissman persona non grata and expelled him.

In a press conference tonight, the military chiefs proposed postponing the election "to reorganize" the troubled Andean nation.There was no immediate reaction form Bolivia's political parties.

The military accused Weissman last week of acting as an "imperial viceroy" in efforts to prevent a coup that reportedly was planned for May 31. The Carter administration has encouraged attempts to implant democratic rule here as an example for other military-dominated countries in South America.

Reporting on Weissmen's behind-the-scenes activity prompted the State Department to declare last Wednesday that "we are aware of reports of a possible coup." Spokesman Hodding Carter III repeated earlier statements that "the United States supports a continued evolution of the democratic process in Bolivia, leading to presidential elections on June 29 and the subsequent inauguration of a new president Aug. 6."

The military, infuriated by what one diplomat characterized as having been "caught with its hands in the cookie jar" -- that is, being publicly remonstrated for planning a coup -- reacted with two public statements attacking the United States.

On Thursday, the high command accused the United States of intervening in Bolivia's internal affairs and Weissman personally of having "overstepped the boundaries" of his diplomatic position. On Saturday, it demanded that the ambassador be declared persona non grata because he "committed grave offense to the dignity of the country."

Many observers here say the military seems to be trying to use latent anti-U.S. sentiment to gain support for a coup against Gueiler's interim government.

The military and the right-wing Falange Party, which in the past have looked to the United States for support, are now leading the campaign against Weissman personally and against the Carter administration's policy of encouraging democratically elected civilian rule.

Bolivia's leftist and centrist parties, while not wanting to be caught in the unaccustomed position of defending U.S. foreign policy, have voiced some support for efforts to see that the scheduled elections are not canceled by a military coup.

Sen. Leonidas Sanchez, vice president of the Senate and a leader of the centrist National Revolutionary Movement of former president Victor Paz Estenssoro, said today that the U.S. statements did not constitute intervention in Bolivia's internal affairs.