MEXICO CITY - Mexican President Felipe Calderon and his visiting Colombian counterpart Juan Manuel Santos inked several agreements here Monday to enhance cooperation against the organized crime.

The two presidents lauded existing bilateral cooperation in that area, which, they said, made the two countries "more united than ever."

"We are closing the criminal organizations' space," Calderon told reporters, adding that the transnational organized crime poses "one of the greatest challenges our countries have."

For his part, Santos said the signed agreements would also benefit Central American and Caribbean countries.

He urged continued efforts to combat crimes so that drug cartels in his country could be eliminated in several years. "Don't stop the fight, it is an expensive one. But if you want to succeed, you have to persist."

Santos arrived here Saturday for an official visit which runs through Thursday.