HAVANA — President Vicente Fox of Mexico trod lightly on sensitive diplomatic territory on Monday, ending his goodwill mission to Cuba by meeting with several of its government's most prominent opponents.

In a statement after the meeting, Fox pressed Cuba's government, the last communist one in the region, to pursue democratic reforms and increase human rights protections.

Fox, whose election 18 months ago ended the 71-year rule of Mexico's Institutional Revolutionary Party, held several hours of private conversation with President Fidel Castro, who has been in power for 43 years. Fox said he was particularly interested in seeing Cuba abolish the death penalty.

"I expressed my hope that Cuba can move toward the standards on human rights and democracy that, day by day, help make things more secure not only in Latin America but in the rest of the world," Fox said. He said that he told dissident leaders that he was "always ready to hear all the voices of Cuban society."

Elizardo Sanchez, president of the Cuban Commission on Human Rights and National Reconciliation, said that the meeting provided important recognition for the efforts of Cuban dissidents. Their organizations are not recognized by the Cuban government. Many dissident leaders have been imprisoned for their activities.

"The government tries to treat us as if we do not exist," said Sanchez, a former professor of Marxism at the University of Havana. "The visit with President Fox demonstrates that we are here and it gives us a voice."

Fox said Castro "accepted it as a right that we have and he accepted that I have a very strong commitment with human rights and with democracy."

The Cuban foreign minister, Felipe Perez Roque, said after Fox departed, 'We are satisfied with the visit." He said that the two countries had agreed on the need to increase trade and other forms of cooperation, and on "respect for sovereignty."

Fox is the first Mexican head of state to meet in Havana with dissident leaders. Walking the incendiary line between Washington and Havana, Fox made important gestures toward both.