The United States is actively exploring a revival on an amended basis of its foreign aid and security relationship with Pakistan, a senior State Department official said last night.

According to the official, who would not permit use of his name, careful study of a recent statement by Pakistan's foreign affairs chief, Agha Shahi, disclosed interest in renewed U.S. economic aid and security commitments, even though the terms of proposed U.S. military aid are unacceptable.

Following incomplete press accounts of Shahi's address last Wednesday in Islamabad, the State Department said it had no plans to go forward with legislative authorization for a Parkistani program because that country had indicated it was "not interested" in the U.S. assistance as originally proposed.

The idea of salvaging part of the U.S.-Pakistani relationship, even while leaving military aid in limbo, is being explored with the government in Islamabad through diplomatic channels, officials here said. There is no clear sign in official exchanges whether the amended plan will succeed, according to U.S. sources, though they said there are favorable indications from unofficial soundings.

The revival of a Pakistani aid-and-security plan would rescue the Carter administration from the embarrassment of having proposed a major aid program for a threatened country abroad, only to be turned down flat.

Pakistani sources have suggested that the high-visibility nature of the administration plan -- which was heralded in President Carter's State of the Union address, several official statements and briefings before being worked out with Pakistan -- was a major problem.

The Islamabad regime appeared to feel that its status as a nonaligned nation was being jeopardized without assurance that it would receive the sort of large-scale, long-term American assistance needed to guarantee its security as an American ally.

The package proposal originally presented to Islamabad by the administration was in three parts: reaffirmation by Congress of a 1959 U.S. security commitment against communist military threats to Pakistan, $200 million in U.S. economic assistance over two years, and $200 million in U.S. military sales credits over two years.

Shahi, in the full text of his recent address, said Pakistan had been informed that the first two parts of the U.S. package were "inseparably linked" with the unacceptable military aid U.S. officials conceded that the three elements were presented together during a visit to Pakistan last month by presidential assistant Zbigniew Brezezinski and Deputy Secretary of State Warren Christopher.

The U.S. bid for a revival of the aid plan on a partial basis might resolve the dispute between the two nations if Pakistan is willing to proceed, official sources indicated.