The foreign ministers of all five Central American nations met in Panama today as part of a joint initiative by Mexico, Venezuela, Colombia and Panama to discuss possibilities for a negotiated solution to the region's worsening crises.

"We believe just the fact of getting together the Central American foreign ministers is a very positive step," Venezuelan Foreign Minister Jose Alberto Zambrano said last night.

The United States, which is deeply involved in the area's confrontations, was intentionally excluded from the current initiative and has not objected.

Washington-backed efforts to promote regional peace last year, especially the creation of a Central American Democratic Community made up of El Salvador, Honduras and Costa Rica, were attacked by Nicaragua's revolutionary Sandinista government as efforts to isolate and pressure Nicaragua rather than to find a peaceful solution to the area's problems.

The Sandinistas' own initiative, on the other hand, emphasized bilateral talks with neighboring Honduras and Costa Rica while disregarding U.S. concerns about Sandinista backing for revolutionaries in El Salvador and Guatemala.

The efforts of what is called the Contadora Group, named after the Panamanian resort island where the foreign ministers of Mexico, Venezuela, Colombia and Panama first met to address these problems in January, are aimed at breaking the diplomatic standoff. The initiative has assumed a special urgency since rebels fighting the Sandinistas in Nicaragua with U.S. and Honduran support have stepped up their activities, which has increased fears of open warfare between Nicaragua and Honduras.

Last week the four Contadora foreign ministers flew to every Central American capital to lay the groundwork for today's meeting. Thus far, Washington has remained quiet on this latest peace initiative, which appears to be advocating solutions at least superficially similar to those proposed by the Salvadoran and Honduran foreign ministers last year.

Key provisions of those proposals include the removal of all foreign military advisers from Central America--understood to be Cubans and East Europeans in Nicaragua and Americans in the rest of the region. Other proposals call for an end to the arms race in the area and advocate the peaceful resolution of conflicts through negotiation.

A complicating factor is the question of internal negotiations in El Salvador. The Salvadoran government, with Washington's support, consistently has refused to negotiate with leftist insurgents. Mexico, however, has supported negotiation between the Salvadoran government and the rebels seeking to overthrow it as the best means of ending El Salvador's 2 1/2-year-old civil war.

Some diplomats in the region view the Contadora initiative as deeply and inherently at odds with current U.S. policy because it would tend to diminish overall U.S. influence in the area and endorse the status quo in Nicaragua, which Washington views as dangerously Marxist. U.S. policy has been directed in recent months not only toward stopping Nicaragua's export of revolution but also toward changing the increasingly leftist orientation of the revolution inside Nicaragua.

"If the United States were willing to relinquish some power and show some flexibility, it might be able to achieve all sorts of things," said one diplomat familiar with the current initiative. "It might gain stability and improve its regional relations."

But the same diplomat suggested that a "great danger" of the current talks is that they will move so far from Washington's policy objectives that it will feel compelled publicly to show its opposition. In such a case its relations with Colombia, Mexico, Venezuela and Panama could suffer serious setbacks, the diplomat speculated.