Nicaraguan Ambassador Carlos Tunnermann, expelled by the United States after Nicaragua kicked out the U.S. ambassador, arrived Friday in Mexico City calling the move "totally unjustified" and suggesting he will seek its repeal.

Tunnermann said his government had reasons to expel U.S. Ambassador Richard Melton since he sought "the destabilization of a democratically elected government." Tunnermann said that while performing his duties in Washington he had not interfered in internal American affairs."I have never interfered, my work has been totally diplomatic," Tunnermann told reporters gathered at Mexico City's international airport. He left for Managua Saturday.

Tunnermann hinted he would fight the U.S. decision to expel him since he is also accredited as the Nicaraguan ambassador to the Organization of American States in Washington.

"We still have diplomatic relations with the United States and as long as they exist there's room for negotiation," he said. "As far as I am concerned, I am still the permament ambassador to the OAS."

"I consider the expulsion totally unjustified and illegal. The United States has done this in retaliation of the Nicaraguan government's expulsion of Richard Melton, but we had reasons to do this. Melton broke diplomatic conduct and interfered in Nicaraguan internal affairs."

The U.S. expulsions were ordered Tuesday by the State Department after the Nicaraguan government told Melton and seven other U.S. diplomats to leave the country.

The expulsions - just short of breaking off diplomatic relations - raised to a new level the war of words and legal action between Washington and Managua.

Tunnermann had set up a possible legal test for the expulsion, arguing the order was an illegal breach of diplomatic privilege since he also was accredited to the OAS.

In a hearing before the OAS Council, Tunnermann found no solid support, but he vowed to continue his legal fight.

Tunnermann said the decision to leave was partially based on the belief that the U.S. government might use a defiance of the expulsion order "as an instrument for its continued aggression against our people."

"We are defending the principles of OAS and defending the independence of state members to appoint ambassadors," he said.

The expulsion of Tunnermann set the stage for a new administration request to Congress for aid to the anti-Sandinista Contra forces based in Honduras and Nicaragua.