The White House and the State Department joined with visiting President Mobutu Sese Seko of Zaire yesterday in condemning Libyan intervention in Chad, while efforts continued to persuade France to play a bigger military role in the defense of the central African country.

Pentagon officials said that about 30 U.S. Redeye antiaircraft missiles have arrived in Chad and that four American military advisers would use French intermediaries to train Chad's army in their use.

There were also reports that the aircraft carrier USS Coral Sea has delayed its departure from the Mediterranean to stay with a U.S. carrier battle group operating off Libya.

Officials yesterday dismissed Libyan threats to sink the carrier USS Eisenhower, part of the same battle group, after an incident Monday between U.S. and Libyan planes over the Gulf of Sidra.

State Department spokesman John Hughes said the United States had "no response except to say that we recognize a 12-mile territorial limit and we retain our right to operate in international waters." Libya claims a 60-mile limit, which includes part of the Gulf of Sidra.

Two Airborne Warning and Control System surveillance planes landed in Egypt yesterday, apparently to observe Libyan air activity in the region. The AWACS planes, whose radar enables them to "see" more than 200 miles, are to take part in U.S.-Egyptian exercises starting next week, but Pentagon sources told the Associated Press the planes had arrived early because of concern about the situation in Chad.

At the White House, spokesman Larry Speakes reiterated U.S. policy on the fighting in Chad, saying "we condemn it in the strongest fashion." A senior State Department official warned that if Libyan "aggression" succeeded in Chad, other countries in the region would be threatened.

"If that kind of activity passes without response . . . it will feed upon itself and pose a threat to the stability and security of a rather large number of states," said this official, who spoke on condition that he not be identified. "One could just look at the map and see Sudan, Tunisia, Egypt, Niger--and the list goes on."

Reports from Chad yesterday said that Libyan planes continued to bomb government forces in the strategic northern oasis of Faya Largeau, using fragmentation and phosphorous bombs.

U.S. officials said that the Libyans were not only providing air support for the forces of insurgent leader Goukouni Oueddei, but also were involved on the ground in combat and logistical roles.

Intelligence reports showed increased Libyan activity on each side of the Libya-Chad border, a factor that officials said would have to be taken into account in determining further U.S. responses.

The State Department said it could not confirm a Libyan claim that Chadian President Hissene Habre had been killed in the bombing. "We think that report is incorrect," Hughes said. Chad earlier denied the report.

Mobutu, who has sent 1,800 troops and six aircraft to support the Habre government, told reporters yesterday that he believes the situation in Chad "is getting worse, particularly with the intensification of the bombing raids on the civilian population of Faya Largeau . . . . "

Mobutu lunched at the State Department with Vice President Bush, Secretary of State George P. Shultz, CIA Director William J. Casey and other senior U.S. officials. He is to see President Reagan today.

U.S. officials praised Mobutu for his "courageous action" in sending troops to Chad and said that Zaire was not being asked to increase its contribution to Chad's defense. They said that some of Zaire's expenses had been met out of $7 million in emergency U.S. aid to Habre.

Officials indicated that the Reagan administration is continuing to urge France to give aerial cover to Chadian government forces, but there has been little response.

France, like the United States, has sent antiaircraft weapons but is wary of sending combat aircraft to Chad. Diplomatic sources said the French had made clear to the United States that if Habre had to rely on foreign military assistance to defeat the Libyan-backed rebels, his position in Africa could be seriously undermined.

The French airlifted a large amount of war materiel to Chad last month but say that they are not bound by a 1976 military cooperation treaty to defend the country.

"The Americans would certainly like to see France play a role which the Socialist government" of President Francois Mitterrand "cannot play in Africa for obvious reasons," said one diplomat. "France could solve the problem militarily but not politically."