KARACHI.-Pakistan President Agha Yahya Khan said today that "nobody wants war" since it would solve nothing. Yahya said he believes Mrs. Gandhi did not want a war despite her recent statements.

Yahya told journalists that he would announce a plan within a few weeks to turn over governmental power in Pakistan to representatives elected last December. He also offered amnesty to members Of the secessionist Awami League who did not commit crimes in the initial fighting last March in East Pakistan.

He said President Nixon had offered Pakistan aid in what Yahya called a "warmhearted, kind, personal letter of friendship," received Saturday.