El Salvador on Monday offered to house in its jails "dangerous criminals" deported by the United States, U.S. Secretary of State Marco Rubio said after lengthy talks with the Central American country's leader.

Rubio, who is on his first oversees tour as the U.S. top diplomat, is seeking support from countries in the region for the Trump administration's attempts to deport large numbers of migrants.

He met with El Salvador's President Nayib Bukele and senior officials at Bukele's residence on Lake Coatepeque outside the capital for almost three hours, where they agreed to go beyond El Salvador's acceptance of its own deported citizens.

"Any ... illegal immigrant in the United States who’s a dangerous criminal - MS-13, Tren de Aragua, whatever it may be - he has offered his jails, so we can send them and he will put them in his jails," Rubio said, referring to members of criminal gangs.

Bukele also offered to house dangerous criminals who are U.S. citizens or legal residents, Rubio said, although it was unclear whether the U.S. would take up that offer.

Rubio said more details of the agreement would be forthcoming.

Bukele said in a post on X that he had offered the U.S. "the opportunity to outsource part of its prison system".

"We are willing to take in only convicted criminals (including convicted U.S. citizens) into our mega-prison... in exchange for a fee," he wrote shortly after Rubio's announcement, referring to El Salvador's so-called terrorism confinement center.

"The fee would be relatively low for the U.S. but significant for us, making our entire prison system sustainable."

Bukele is seen by the Trump administration as a key ally in its migration efforts in the region. The Salvadoran president has launched an unflinching security crackdown in his country, arresting more than 80,000 people, and bringing the number of homicides down sharply. His policies are credited by Washington with reducing the number of Salvadorans seeking to enter the U.S. illegally.

Since taking office on Jan. 20, the Trump administration has stepped up the number of migrants the U.S. deports to Latin America, including using military planes for repatriation flights.