Fidel Castro Monday participated in a number of activities?in Havana?to celebrate the Cuban Revolution Day, which falls on July 26.

According to the official NNTV news channel, Castro, 83, laid a wreath for the national hero Jose Marti in the morning and then met with local artists, intellectuals and religious friends, as well as activists from the United States.

During an hour-long meeting with a delegation of the U.S. religious organization "Pastors for Peace" headed by Lucius Walker, the former Cuban leader recalled how he led the attack against the Moncada and Carlos Manuel de Cespedes military barracks on July 26, 1953.

The U.S. delegation arrived in Cuba on Friday along with 100 tons of humanitarian aid.

Castro, wearing an olive-green military shirt, said he is now writing a book on his guerrilla experiences.

He also made comments on issues such as the tension between the United States and Iran as well as the oil spill in the Gulf of Mexico, saying he is preparing new "reflections" on these topics.

In the last three weeks, Castro made a series of public appearances after staying out of the public life for four years since he handed power to brother Raul in 2006.