HELSINKI, FEB. 20 -- Secretary of State George P. Shultz said today that the United States, the Soviet Union and other major powers will officially consider a U.N.-sponsored arms embargo against Iran, and he declared "it is time to move" to international intervention in the seven-year-old Iran-Iraq war in the Persian Gulf.

On the eve of the first top-level U.S.-Soviet discussions since the Washington summit two months ago, Shultz said the five permanent members of the United Nations Security Council have begun circulating the text of the long-delayed arms embargo plan and that the United States is "pushing as hard as we can" to bring it to a vote before the end of this month.

The Soviet Union has been delaying a decision since last September on the potentially far-reaching embargo.

Shultz made clear he will press for its approval in his discussions Sunday and Monday with Foreign Minister Eduard Shevardnadze and Soviet leader Mikhail Gorbachev.

A draft of the proposed action, which calls for a halt in the sale of arms, spare parts, arms manufacturing facilities and military training services to Iran, began circulating at the United Nations late Friday, aides to Shultz said.

"You get something officially up and on the table" by circulating the plan, said Shultz.

While Shultz lobbies the Soviets as part of an American drive on the Persian Gulf issue, Iraqi Deputy Prime Minister Tariq Aziz will be in Beijing to make the case for the embargo to the similarly reluctant Chinese government.

U.S. diplomats also have been instructed to take up the issue with the other members of the 15-nation Security Council.

The arms embargo and the situation in the Persian Gulf are part of an extraordinarily broad agenda of priority items to be discussed by Shultz in Moscow.

All are likely to require intensive diplomatic efforts and consultations with the Soviets in the final 11 months of the Reagan administration.

Far from being the quiet twilight of an administration about to leave office, the months between now and the next U.S.-Soviet summit meeting, planned for Moscow in late May or early June, promise to be among the most intense of the eight years of diplomacy in the Reagan era.

That intensity may continue through the summer and fall.

Shultz's travels, which reflect this broadened agenda, will take him from the Moscow discussions to the Middle East next week for an attempt to initiate new Arab-Israeli negotiations.

Then he is due at a NATO summit meeting in Brussels to discuss the drive for a treaty to cut in half the U.S. and Soviet strategic nuclear arsenals.

The most dramatic new development in U.S.-Soviet affairs was Gorbachev's announcement Feb. 8 that the Soviet Union is ready to begin withdrawing its troops from Afghanistan by May 15, and will do so over a 10-month period if U.N.-sponsored negotiations on Afghanistan can be completed by March 15.

"A definite commitment to withdraw Soviet forces is the key we've been looking for," Shultz told reporters during his journey here today.

He said he wants to explore details of the Soviet pullout in Moscow before committing the United States as a guarantor of the U.N. plan, which calls for a cutoff of arms to the Afghan resistance as Soviet forces begin to leave 60 days after the agreement is signed.

Shultz dealt cautiously with Pakistan's sudden demand that an interim government be established in the Afghanistan capital of Kabul before the peace accords are signed.

An interim government is "desirable," Shultz said. But neither he nor his senior aides would say whether the United States would back Pakistan if its demand delayed the Soviet pullout.

Iran, which borders Afghanistan as well as the Soviet Union, is an important factor in virtually all regional issues.

U.S. officials believe that the strategic importance of Iran to Moscow is the basic reason for the Soviets' reluctance to impose an arms embargo aimed at pressing Tehran to moderate or stop its war with Iraq.

Last July, the Soviet Union joined the United States and other Security Council members in a U.N. resolution demanding that both Iran and Iraq stop fighting and return to international boundaries.

Attempts to impose sanctions against Iran followed Tehran's refusal to agree, although Iraq said it was willing to accept the U.N. demand.

The administration promised Saudi Arabia's foreign minister, Prince Saud Faisal, to make an all-out push for adoption of the arms embargo while the United States holds the rotating presidency of the Security Council this month.

Shultz placed major importance in his remarks on continued unanimity in the Security Council, suggesting that the United States might not push the proposed embargo to a vote if he finds that despite his impending pleas and Arab pressures, the Soviet Union still balks at adopting strong measures against Iran.

Efforts to complete a new strategic arms treaty before the next summit meeting had been expected to dominate Shultz's Moscow mission.

But Afghanistan and Persian Gulf developments and the intense Soviet interest in U.S. maneuvering in the Arab-Israeli dispute are expected to have at least equal importance.

Shultz said he hopes to "energize this process" of strategic arms negotiations after a period in which the Soviets seemed to be "dragging their feet a little" in the Geneva arms talks.

Shultz said the strategic arms negotiations are in a stage of "detailed work," making a major or dramatic breakthrough unlikely.

He said the central issues at the moment concern verification of the proposed strategic arms pact, which would make the intensive and complex verification arrangements of the recent Intermediate-range Nuclear Forces (INF) treaty "seem like child's play."