WASHINGTON — The Reagan Administration said Tuesday that the United Nations should impose sanctions promptly against Iran if it does not accept a cease-fire in the Persian Gulf War by the end of this week.
The Administration's top Middle East expert conceded, however, that Iraq may have squandered some of its support in the United Nations by resuming attacks on tankers in the gulf.
If, by Friday, Iran does not unequivocally accept the July 20 U.N. Security Council resolution calling for a cease-fire in the seven-year-old Iran-Iraq War, the council should begin early next week to draft a resolution imposing sanctions, probably including an arms embargo, State Department spokeswoman Phyllis Oakley said.
Oakley said that the Friday date was selected because Iran has promised to deliver its formal response to the Security Council resolution on that day. She said the sanctions should be imposed only on Iran because Iraq already has indicated that it will accept the Security Council's call for a cease-fire, provided Iran does the same.
However, Richard W. Murphy, assistant secretary of state for Near Eastern and South Asian affairs, said that some Security Council members are reluctant to consider sanctions, even though the 15-nation panel voted unanimously for the original cease-fire resolution. He said the American task in persuading the council to impose sanctions was made more difficult by Iraq's resumption of the so-called tanker war.
Shortly after Murphy spoke, a Soviet official visiting Washington said that Moscow wants to allow more time for diplomacy before considering sanctions.
Murphy said the United States had urged Iraq to prolong its 45-day pause in attacks on shipping at least until the Security Council has acted on the sanctions proposal. Diplomatic sources said that Murphy called for restraint in a meeting Saturday with Iraqi Ambassador Nizar Hamdoon but that Iraq rejected the U.S. advice.
Iraqi Raids 'Unfortunate'
"Iraq had captured the high ground, had persuaded the international community it was ready to go to negotiations," Murphy said. "We felt that it was unfortunate that Iraq felt obliged to resume its attacks a few days before the return of the Iranian answer (to the Security Council)."
Murphy, interviewed by Arab journalists on the U.S. Information Agency's Worldnet satellite broadcast, said that Washington "did not ask and we do not expect Iraq to stand down indefinitely" in the tanker war unless Iran agrees to a comprehensive cease-fire.
Murphy conceded that an arms embargo would not bring an immediate end to the Iranian war effort because Tehran has a large stockpile of weapons. But he said that such an embargo would put pressure on Iran and demonstrate international determination to end the war.
At the same time, Murphy said it would do little good for the United States to ban imports of Iranian oil. The Administration is known to be considering such an embargo, which is supported by the Pentagon.
"We have discovered, not surprisingly, given the nature of the spot market, that it is extremely hard to trace back the origin of oil once it enters international trade," he said, disclosing for the first time the State Department's position in the internal debate.
Under the U.N. Charter, any of the five permanent members of the Security Council--the United States, Britain, France, the Soviet Union and China--can veto a resolution. U.S. officials concede that it will be difficult to win Soviet and Chinese support for an arms embargo because China and several Eastern European nations have supplied weapons to Tehran.
At a Washington press conference, Vladimir F. Petrovsky, a deputy Soviet foreign minister, made it clear that Moscow is not yet ready to impose mandatory sanctions.
"The situation there (in the gulf) is very dangerous," Petrovsky said. "It is necessary to fulfill to the utmost the decision of the Security Council to display restraint. It concerns, in particular, the United States. Increasing its naval presence gives the wrong background for the mediation purposes of the secretary general."
Petrovsky said that the resumption of Iraqi attacks on shipping makes it imperative to "create the necessary international environment" in which U.N. Secretary General Javier Perez de Cuellar can try to mediate between Tehran and Baghdad.
Meanwhile, the Pentagon announced that the sixth convoy of U.S. Navy-escorted Kuwaiti tankers has completed its voyage through the gulf, reaching port in Kuwait, where the tankers Chesapeake City and Surf City, re-registered under the American flag, will be loaded with petroleum products. Although the trip was described as uneventful, Pentagon officials said that helicopters from the amphibious assault ship Guadalcanal conducted mine-search operations ahead of the ships.
At the same time, the Defense Department said that the refurbished battleship Missouri, accompanied by five escort ships, arrived on station in the northern Arabian Sea near the entrance to the gulf.