President Mohammed Zia ul-Haq of Pakistan arrived in Tehran yesterday on an Islamic "peace mission" to end the Iranian-Iraqi war, but Iranian officials continued to reject all mediation attempts on the grounds that Iraqi was the aggressor.

Zia's mission was one of several peacemaking efforts under way yesterday, none of which seemed close to ending the six-day-old war. Cuba, the Palestine Liberation Organization and the U.N. Security Council were also involved in efforts to resolve the two Persian Gulf neighbors' territorial dispute.

At U.N. headquarters in New York, Security Council delegates were conducting consultations before a proposed formal council session that was to adopt a resolution reaffirming the body's earlier cease-fire call.

However, Iran's acting Chief U.N. delegate, Jalal Shemirani, said in a telephone interview that his country does not accept the language of a Security council resolution already prepared by Norway and Mexico.

Shemirani said Iran would only accpet a Security Council resolution that condemned Iraqi "aggression" against Iran and called on Baghdad to withdraw its troops from Iranian territory.

[The Associated Press reported late Saturday that the Security Council postponed action on the resolution.]

The resolution prepared by Norway and Mexico called on Iran and Iraq to "refrain immediately from any further threat or use of force and to settle their dispute by peaceful means," according to council sources. It also encouraged both countries to "accept any appropriate offer of mediation or any assistance . . . that would permit the fulfillment of their [U.N.] Charter obligations."

Shemirani, who did not attend an inconclusive Security Council meeting Friday night, said, "It's up to Iraq to stop all acts of aggression and pull back. We can't accept any offer of mediation." He charged that since Iraq started the war against Iran, a ceasefire resolution addressed to both countries would "disregard the reality of the situation" and would be "one-sided."

U.N. officials said that Security Council members were divided yesterday on whether to go ahead with a formal resolution or leave the peace-making effort with Islamic nations for the time being.

In Tehran, President Zia, representing the 40-nation Islamic Conference, was greeted at Tehran's bomb-damaged Mehrabad Airport with full military honors by Iranian President Abol Hassen Bani-Sadr. Zia and Islamic Conference Security General Habib Chatti of Tunisia were appointed at a meeting of the Moslem grouping in New York Friday to undertake "good-will" visits in both tehran and Baghdad to seek an end to the conflict.

Before leaving for Tehran, Zia called his trip "a peace mission to listen to their point of view and to know if we can contribute something."

At a Tehran news conference yesterday, Prime Minister Mohammed Ali Rajai reiterated Iran's rejection of any mediation and said he regarded the conflict with Iraq as a jihad, or holy war "between Islam and blasphemy." t

Meanwhile, PLO chief Yasser Arafat and two top aides, in Tehran on a seperate peacemaking mission, conferred with Bani-Sadr for 5 1/2 hours. No details of their talks were immediately available.

While spurning any negotiations with Iraq, Rajai said, "We will provide facilities for anybody who is willing to come and see the evidence of the crimes of Saddam," a reference to Iraqi President Saddam Hussein.

Rajai did not rule out an eventual Iranian incursion into Iraqi territory.

"Since we believe Saddam Hussein is a nonbeliever and is ruling by force, our view is that as long as this obstacle is in the way of God, we will advance," Reuter news agency quoted Rajai as saying.

Rajai expressed indifference in response to questions about Iran's future oil exports following Iraqi air strikes that closed the main Kharg Island export terminal earlier this week.

"In this fighting we do not think whether we can export oil in the future or not," he said. "We think of ways that we can live in the future."

Rajai said the oil question was of greater concern to Western countries than to Iranians. "We had no oil before," he said. "We can very well continue to live without oil."

The Iranian premier also blamed the United States for the war, charging that Saddam Hussein was Washington's "intermediary." He said Iraq's contention that Iran had precipitated the war by violating the 1975 Algiers accord between the two countries for a "baseless excuse" for Iraq's attack.

"We had already made known to Iraq that we were ready to solve this difference both on the political level and the international scene," Agence France-Presse quoted Rajai as saying.

In other developments coinciding with the Iranian-Iraqi conflict:

Bani-Sadr said Iran needed more foreign journalists to cover its side of the war, as the Iranian government appeared to be preparing to readmit reporters. "We need them if we want to export our revolution," Bani-Sadr said in a broadcast interview.

Iraq has accepted an offer from Cuba to mediate in the conflict. Havana announced, and Cuban Foreign Minister Isidoro Malmierca was on his way to Tehran after conferring with the Iraqi leadership in Baghdad.

A spokesman for British Prime Minister Margaret Thatcher said Britain would participate in a conference on the security of the Hormuz Strait if such a meeting were arranged.

The chairman of the U.S. Joint Chiefs of Staff, Gen. David Jones, arrived in Saudi Arabia on a five-day visit that U.S. officials said was previously arranged and part of regular consultations.