The White House suggested yesterday that if Congress persists in blocking President Carter from imposing fees on foreign oil, the administration might resort to a system of quotas to restrict imports.

Presidential press secretary Jody Powell said neither import fees nor quotas have been ruled out by the administration as an alternative should Congress fail to enact Carter's national energy legislation.

The president's ability to impose new import fees was threatened Tuesday when the Senate approved a rider to an appropriations bill forbidding such action. Under the legislation, Carter would still be free to impose quotas on imported oil, which would theoretically have similar effects.

The president is under pressure from U.S. allies to reduce American reliance on imported oil, as heavy oil imports have contributed to the decline in the value of the dollar. He is being pressed to promise, during an economic summit conference he will attend in Bonn July 16-17, that he will impose new import fees or quotas on oil should Congress continue to refuse to enact the energy legislation.

It is unlikely, however, that the issue of Carter's ability to impose higher fees will be settled by the time he leaves for Bonn. The Senate prohibition is not part of the House-passed version of the bill and will have to be worked out by a conference committee. But the committee is not likely to begin meeting until a few days before Carter's scheduled departure.

Powell said the Senate action "certainly does not help the president represent the best interests of the United States at Bonn." He also referred to U.S. military personnel in Europe, some of whom Carter will visit during his trip, who have suffered economically, because of the decline in the value of the dollar.

"American soldiers have suffered severely because of the lack of self-discipline by people here who they are over there to defend," Powell said.