NEW YORK (AP) _ In the wake of recent developments in the United States and closer to home, President Daniel Ortega of Nicaragua has repeated accusations that the Reagan administration is plotting to invade his country.

Ortega cited as evidence of the impending invasion the expansion of U.S.-Honduran military maneuvers and the U.S. withdrawal from the World Court case in which Nicaragua accused it of aggression, The New York Times reported today.

The Central American leader also blamed the United States for ending talks between the two countries and said the United States had returned to a hostile attitude toward the Sandinista government.

''All of these point to the fact that the administration has not decided in favor of a political solution and has not discarded a military solution,'' the 39-year-old president said.

Ortega's charges come on the heels of a meeting of several rebel leaders last week in Miami, which produced reports that the Reagan administration was attempting to organize a unified opposition against the Sandinistas.

If such a unified coalition were formed, the administration might have a better chance of securing operational funds from Congress, which last year held up aid to the CIA-trained rebels.

Ortega said increased aid to the rebels would be ''extremely grave for the future of negotiations in Central America.

''That would bring us closer and closer to direct acts of aggression by the United States against Nicaragua.''