Mexican President Jose Lapez Portillo today denied there had been any U.s. pressure on Mexico to grant exile to the deposed shah of Iran, but strongly criticized the Carter administration for its "disorderly" and "precipitious" freezing of Iranian assets in the U.S.

Speaking at a news conference, Lopez Portillo said this "aggressive response of the United States," was a precipitous decision which will seriously debilitate the international monetary system." He said the U.S. freezing of Iranian funds would make oil-producing countries "think twice before they exchange a real resource in the ground for a currency which devaluates and besides is frozen.

With the public attack on the dollar today, the Mexican president appears to be joining other oil-producing nations which have sought to end the pegging of world oil prices to the U.S. dollar.

"Why should we get oil out of the ground to convert into such a precarious monetary symbol as the dollar is proving to be?" the Mexican president asked. m

He called the failure of the United nations to resolve the current U.S.-Iranian crisis "alarming" in its "very dangerous mix of politics, religion and oil," and said that Western nations could not risk war in the Middle East since this would leave Europe without oil. He said the risks in this crisis were "ferocious and the responses are disorderly. This includes the aggresssive decision by the United States to freeze Iran's funds."

Five days ago, on what seemed to be the eve of the deposed shah's return to his exile in Mexico. Lopez Portillo abruptly changed his mind and stunned the United States by sending word to the shah that he was no longer welcome here.

In response to questions, Loper Portillo said there have been "no pressures from the United States. This was an absolutely independent decision."