Panamanian President Ricardo de la Espriella, after meeting yesterday with President Reagan, said his government firmly supports a Mexican-Venezuelan call for Central American peace talks including the United States.

Espriella took office two months ago in what a high-ranking Panamanian official described at the time as a "constitutional coup" and a shift to the right. But the former vice president's speech at the Press Club indicated that his policy on Central America is closer to that of Mexico, which has been at loggerheads with the United States.

Asked about the Mexican-Venezuelan call for talks to resolve differences between the civilian government of Honduras and revolutionary Nicaragua, Espriella said he has joined Costa Rican President Luis Alberto Monge in endorsing the initiative: "We believe in a peaceful resolution . . . in dialogue."

Honduras and Nicaragua have given at least conditional support to the plan but the United States has not responded. Asked about the Marxist rule in Nicaragua, a regional antagonist of the Reagan administration, Espriella said he could support the rule in Managua "as long as the Nicaraguans keep Marxism for themselves and don't try to impose it on anyone else."

The U.S.-educated lawyer sidestepped a question on whether Panama would join a new Community of Democratic Countries in Central America but said, "Real democracy in the area is necessary to consolidate peace."

Espriella, 48, devoted his speech to what he described as the successful U.S.-Panamanian cooperation under the 1977 canal treaties. His predecessor, Aristides Royo, had become increasingly critical of U.S. performance there -- as well as in El Salvador -- prior to the sudden announcement of his resignation July 30.

"There is one problem that could create difficulties," he said. "That is the dual system of wages established by the Panama Canal Commission . . . employes performing the same function, side by side, receive different salaries."

Espriella said that at his half-hour meeting at the White House, "I told President Reagan that we knew he opposed the treaties. But we are proud of the way he has supported them." A U.S. official, quoted by The Associated Press, said Reagan welcomed the "new direction" in Panama toward Central America and was looking forward to a close relationship.

At the Press Club, the Panamanian stressed that "social and economic injustice" are the "principal source of conflict" in the region. Asked whether he could support Reagan's policy in El Salvador, he said: "It depends on President Reagan, it depends on his policy. If President Reagan is interested in real democracy in El Salvador, then we will support" him.