Mexico and Costa Rica unveiled their Strategic Association Accord and signed a series of pacts to effectively "erase" their borders so the two countries can fight as one against organized crime in a region where Mexican drug cartels cast an ever greater shadow.

After the start on Monday of Costa Rican President Laura Chinchilla's two-day visit to the Mexican capital, the leaders of the two countries signed an extradition treaty and an agreement to exchange intelligence and experiences in order to more effectively combat organized crime and drug trafficking.

They also ratified a treaty for the recovery and return of vehicles and aircraft either stolen or used to commit crimes.

Chinchilla, who was officially received by President Felipe Calderon at his official residence of Los Pinos, said that citizens' security "has become a vital issue in the entire Mesoamerican region."

The pacts signed with Mexico "will permit us to combine and strengthen our efforts, have a richer exchange of intelligence, improve the coordination between different corps" of police and the judiciary, and speed up the process of extradition, Chinchilla said.

Central America "has been prey to this evil convoy of death, corruption and intimidation that is organized crime," Chinchilla said, but added that nations of the area "are perfectly prepared to oppose it in a coordinated, organized way."

The criminals "have been capable of ignoring any and all borders" to commit their crimes and, in response, the countries of the region "are also erasing their borders by strengthening the mechanisms of cooperation," the Costa Rican president said.

"It is here in Mexico and Central America where we are truly undertaking a heroic battle against organized crime," Chinchilla said.

Central American authorities have detected the expansion of Mexican cartels in the region, now the principal corridor used by drug traffickers to smuggle Colombian cocaine to the United States.

For his part, Calderon slammed the recent acts of violence in his country and said that the activities of Mexico's drug cartels are getting "more intense and more defiant."

Organized crime groups and drug traffickers together "constitute one of the main challenges" to the "democratic governments" of Latin America, which is forcing countries here to "work together and present a common front to put a stop to what they are doing," Calderon said.

Chinchilla's visit comes in the context of the enactment Sunday of the Strategic Association Accord between Mexico and Costa Rica, an instrument agreed upon in July 2009, which strengthens political ties, cooperation, trade and investment between the two countries.