“I understand that CELAC counts the defense of democracy and human rights among its objectives,” Jorge Jaraquemada, head of the Jaime Guzmán Foundation, told The Miami Herald. “It seems a little contradictory that a Marxist dictatorship that’s been in power for 54 years should preside over an organization with those kinds of objectives.”

U.S. Rep. Ileana Ros-Lehtinen, R-Miami, said in a statement that it was “shameful that democratically elected leaders would share a forum with a murderous tyrant.”

“Latin American leaders claim to support democracy but yet fail to condemn the Castro dictatorship for not allowing free, fair, and transparent elections in Cuba after 50-plus years of brutal oppression,” she said.

Castro arrived shortly after 6 p.m. local time amid tight security. A police guard has been set up outside the Cuban embassy and will remain in place until Monday.

He is among about 40 heads of state from 60 countries attending the summit. German Chancellor Angela Merkel and Spanish Prime Minister Mariano Rajoy are also be in Santiago, along with most of the leaders of Latin America and some Caribbean countries.

The summit is likely to be dominated by economics and trade, given the eurozone’s current woes and the importance of the EU as an investor in Latin America. The bloc accounts for 43 percent of all direct foreign investment in the region — that is more than it invests in China, India and Russia combined.

This year promises to be key for EU-Latin American trade. Until now, only Chile and Mexico have signed Free Trade Agreements with the EU but before the end of 2013, they should be joined by Colombia, Peru and Central America.

Aside from the controversy over the Guzmán murder, Castro will likely be pressed for details of the health of Venezuelan President Hugo Chávez. He has not been seen in public since undergoing treatment for cancer in Cuba last month.