Iraqi Deputy Prime Minister Tariq Aziz said yesterday that he has asked President Reagan to take a personal hand in persuading U.S. allies in Western Europe and Japan to diminish their dealings with Iran to reduce the level of violence in the four-year-old Persian Gulf war.

Aziz said this was "the most important question" he discussed with Reagan and other senior U.S. officials as the United States and Iraq resumed diplomatic relations after 17 years of official estrangement.

"If the U.S. administration takes strong, active steps with its allies it would help in shortening Iran's capability to continue the war and its policies in the region. It won't lead to a direct way to ending the war but it will limit the capability of Iran to continue," Aziz told a breakfast meeting with Washington Post editors and reporters.

Aziz said administration officials seemed to agree "in theory" to make greater efforts to isolate Iran economically and militarily but that "I can't judge exactly what they will do."

The administration has been making a quiet effort for more than a year to stop the flow of arms and other aid to Iran from U.S. allies. This activity, led by Special Ambassador Richard Fairbanks and the State Department, was cited by Aziz as contributing to an improvement in U.S.-Iraqi relations and ultimately to this week's normalization of diplomatic ties.

The Iraqi official went on to complain that British, West German and Japanese sales to and purchases from Iran are "encouraging Iran to continue their present policies." He said he has sought to convince those countries to change their stands in meetings with British ministers who visited Baghdad and trips by Aziz to Germany and Japan but said additional U.S. help is important.

Iranian Prime Minister Mir Hossein Mousavi was quoted by IRNA, the Iranian national news agency, as saying that the renewal of U.S.-Iraqi diplomatic relations will increase anti-American sentiment in Iran. "U.S. pressure on the Islamic Republic will have no effect other than provoking hatred of the people against the United States," Mousavi was quoted as saying following a Cabinet meeting in Tehran.

A major Iranian ground offensive against Iraq, which has been widely forecast since hundreds of thousands of Iranian combatants took up invasion positions early this year, was expected by many to be the turning point of the war.

"We are still prepared to face a huge offensive in Basra," said Aziz. "We think they [the Iranians] will do it."

"If they don't do it, we think they will attack Kuwait," said the Iraqi official. He said such an Iranian attack would "put the area into a critical situation" and be considered by other nations of the Gulf Cooperation Council, including Saudi Arabia, as the same as an attack against themselves.

Aziz said he sees little possibility that the long-running war will end as long as "the present religious regime" in Tehran remains in power, even after the death of Ayatollah Ruhollah Khomeini. Only a fundamental change in Iran can bring the termination of the war, though outside pressures can have a major effect on its intensity, Aziz said.

The Israeli Embassy, responding to a statement of Aziz Tuesday before the American Enterprise Institute, issued a press release inviting the Iraqi official to visit Israel to "see for himself" that there is no map in the chambers of the Knesset, the legislature of the Jewish state, showing the territory of Israel extending to Iraqi lands in the Tigris-Euphrates valley.

An Iraqi spokesman said Aziz was "not taking seriously" the Israeli invitation, which he said had been issued "for the American public."