The Senate, still at odds over whether to impose war-powers limits on the U.S. tanker-escort operation in the Persian Gulf, yesterday called on the Reagan administration to induce foreign countries that benefit from the operation to help pay for it.

Under the plan proposed by Sen. John Melcher (D-Mont.), both oil-producing and oil-purchasing countries would be expected to reimburse the United States for their pro rata share of the expense of escorting Kuwaiti tankers, which is estimated to be costing the Pentagon about $20 million per month.

The nonbinding proposal was approved 95 to 2 as part of a fiscal 1988 State Department authorization bill, debate on which has encompassed a wide array of foreign policy fights on issues ranging from the Persian Gulf to the Panama Canal.

In other votes on the bill yesterday, the Senate:Approved a proposal by Sen. William V. Roth Jr. (R-Del.) to impose on Eastern European and Cuban diplomats the same travel restrictions that are applied to Soviet officials in the United States.

The proposal was approved by voice vote after the Senate, voting 59 to 37, rejected objections from Foreign Relations Committee Chairman Claiborne Pell (D-R.I.) that the move could lead to retaliation against U.S. diplomats stationed in Soviet-bloc countries.

The restrictions, which could be waived by the president, are aimed at curtailing espionage done for the Soviets by their allies. Voted 59 to 39 to shelve a proposal by Sen. Steve Symms (R-Idaho) that would have reopened the intense controversy that surrounded ratification of the Panama Canal treaties in the late 1970s. Symms' proposal urged President Reagan to void the treaties if Panama does not act within six months to accept reservations that assert U.S. rights to defend the canal after it is transferred to Panama in the year 2000.

The proposal also would have put the Senate on record as saying it made a mistake in approving the treaties. Approved by voice vote a proposal by Sen. John S. McCain III (R-Ariz.) to exempt independent news organizations, labor unions and other democratic institutions in Nicaragua from an embargo that was put on trade with the leftist-led country in 1985. Approved, 66 to 33, a proposal by Sen. Mark O. Hatfield (R-Ore.) to commit the United States to a three-year program providing for annual resettlement in this country of no fewer than 36,500 Indochinese refugees, a move aimed at encouraging other countries to keep providing temporary asylum and at preventing a cutback in admission of refugees to the United States.

In backing a cost-sharing plan for the Persian Gulf, the Senate called on Reagan to begin negotiations on a reimbursement agreement with Kuwait, other oil-producing states in the gulf and countries that purchase oil from the gulf region.

It did not specify how costs would be apportioned, but asked the president to report to Congress on the apportionment formula and progress of the negotiations. The United States has been escorting Kuwaiti tankers that now fly the U.S. flag.

Melcher and other backers of the proposal noted Japan is taking steps to compensate the United States for protecting oil it receives from the gulf and said it was "just good common sense," as Melcher put it, for other countries to do the same.

Sen. Jesse Helms (N.C.), ranking Republican on the Foreign Relations Committee, said he "can almost hear the American people applauding" and joined Melcher in support of the measure.

Melcher emphasized that the proposal was not connected in any way with the dispute over whether to require congressional approval for long-term continuation of the escort operation, which some senators contend is required under the 1973 War Powers Resolution.

A proposal to require such approval remains on the Senate calendar, although Democratic leaders failed last week to break a GOP filibuster against a similar plan.

The Senate, on a voice vote, also suggested an end to cavalcades for foreign dignitaries visiting the Capitol grounds. At the urging of Sen. Daniel Patrick Moynihan (D-N.Y.) the Senate said "two unadorned automobiles and no motorcycles would ensure foreign visitors a warm welcome . . . . "