With regal formality, Japanese Emperor Hirohito welcomed President Carter to the Far East today as American officials here suggested general agreement with a European proposal for an overall limit on oil imports by the United States and its main allies.

The brief welcoming ceremony took place inside Tokyo's Akasaka palace, the official government guest house, and in the expansive, cobblestone palace courtyard where the emperor watched Carter walk along a red carpet to review Japanese troops and greet scores of dignitaries.

The president and the emperor then rode together to the nearby imperial palace, where Carter greeted other members of Japan's Imperial family.

Following these ceremonies, during which he made no public comments, Carter began the first of his meetings with Japanese Prime Minister Masayoshi Ohira at the start of his three-day state visit to Japan.

But even before the visit was officially under way this morning, it was overshadowed by the economic summit conference among the United States and its principal allies that is to start here Thursday.

Energy will top the agenda of the economic summit, which will begin two days after the Organization of Petroleum Exporting Countries, meeting in Geneva, is expected to approve another increase in the world price of oil.

Last week, the nine-member European Common Market agreed to propose at the economic summit that the industrialized democracies freeze oil imports at their current levels for the next five years. The European members of the economic summit group - Britain, France, West Germany and Italy - will bring that proposal to Tokyo and press the other participants - the United States, Japan and Canada - to accept it.

American officials traveling with the president did not speak in terms of an import freeze. But they suggested that if details could be worked out, the United States could support some form of the European proposal for the seven summit nations to act jointly to "level off" their oil imports.

The seven nations currently import about 21 million barrels of oil a day, with the U.S. share of that running at about nine million barrels a day, according to American officials.

Officials also said that Carter is determined to make the plight of the thousands of Vietnamese and other Southeast Asian refugees the second most important issue discussed at the economic summit, and to press the other nations to do more to help the refugees.

"We have to put pressure on Vietnam to behave itself and we have to deal with the staggering human problem," one administration official said.

On the energy and refugee issues especially, another official said, the U.S. will consider the summit a failure if it produces only "bland generalities."

"This whole thing is going to be a bust unless they come out of the summit with specific courses of action," he said. "He [Carter] didn't go all the way to Japan just to have a general discussion, but to reach agreement on a plan that would help Americans."

The president's state visit to Japan is expected to be largely a ceremonial prelude to the difficult problems awaiting him at the economic summit. The biggest differences between the United States and Japan, revolving around questions of trade policy, were generally worked out by Carter and Ohira last month when they met in Washington.

Carter is expected to sound out Japanese government officials on the energy and refugee questions before making his proposals to the other leaders at the summit conference.

The president was accompanied here by his wife, Rosalynn, and their daughter, Amy, who clutched her violin case as she stepped off Air Force One.

This morning's welcoming ceremony took place in a setting more European than oriental and in muggy weather comparable to an August after in Washington.

Akasaka palace is a two-story granite structure built in French architectural style in the early 20th century.

Carter, dressed in a dark blue suit, and Mrs. Carter arrived at the palace at 10 a.m. Their daughter remained in the U.S. Embassy because, officials said, she was not feeling well after the 15-hour flight that began Saturday afternoon in Washington.

Later in the afternoon Mrs. Carter excused herself from a receiving line at Ohira's residence, and officials said she was not feeling well. Dr. William Lukash and Mrs. Carter and Amy were suffering from gastroenteritis, which is an inflamation of the stomach and intestines.

Throughout Tokyo, and particularly anywhere the American party travealed, the streets were clogged with thousands of Japanese security officials. The extraordinary security here is the tightest Carter has encountered as president.

The 20-minute welcoming ceremony at the palace included no public remarks. Carter solemnly reviewed white-uniformed Japanese troops as a military band played marshal music, and he strolled along the receiving line to greet the assembled dignitaries.

As he left the palace in the emporor's limousine, the president waved to a group of Americans who responded by waving small, paper U.S. and Japanese flags that made a restling sound in the air.

The official American party also include Secretary of State Cyrus Vance, Treasury Secretary W. Michael Blumenthal, Energy Secreary James Schlesinger and numerous White House aides. Defense Secretary Harold Brown will join the group Friday in Seoul, where Carter will travel for a state visit to Korea after the economic summit.

One official who normally travels abroad with the president - national security adviser Zbigniew Brzezinski - remained in Washington to monitor "the unsteady situation" in Nicaragua, according to White House press secretary Jody Powell Brzezinski will join the U.S. party here Tuesday, Powell said.

Carter's arrival at the airport was low key and devoid of ceremony. The public was barred from the airport, a sign of the extraordinary security measures in force here that left the streets of Tokyo along the president's motorcade route largely populated by police and other security personnel.

Among those who greeted the president at the airport was former Senate majorty leader and now U.S. Ambassador to Japan Mike Mansfield. Chatting with reporters, Mansfield took the opportunity to berate announced Republican presidential candidate John Connally's assertion that Japan has closed its markets to U.S. goods.

Ticking off figures on the amount of American agricultural products Japan imports, Mansfield said, "They're our number one customers."

The ambassador also said he thinks the United States should immediately impose gasoline rationing to cut down on oil imports. CAPTION: Picture, Leftist demonstrators peform snake dance near Tokyo airport to oppose President Carter's visit. AP