More migrants slated for deportation from the United States have arrived at the detention center at Guantanamo Bay, Cuba, just as U.S. Defense Secretary Pete Hegseth visited the naval base to get an update on mass deportation efforts.

A U.S. cargo plane carrying nine migrants from Fort Bliss in Texas landed at Guantanamo Bay midday Tuesday, a U.S. defense official told VOA.

A second official said all nine passengers are considered "high threat illegal aliens," and they were taken to the detention center there.

A third official said that an additional flight carrying more migrants was tentatively scheduled for Wednesday.

All of the officials spoke to VOA on the condition of anonymity since they were not authorized to discuss the deportation operations.

The new detainees join another 17 detainees sent from Fort Bliss to Guantanamo Bay on Sunday.

Neither the Department of Homeland Security (DHS), which is spearheading the U.S. deportation efforts, nor Immigration and Customs Enforcement (ICE) has so far responded to questions about the identities of the detainees, their countries of origin or the crimes with which they are charged.

Tuesday's flight carrying detainees from the U.S. mainland to the naval base in Cuba is the second since ICE last Thursday deported 177 detainees who had been brought to Guantanamo Bay earlier this month.

Of the 177, officials had said that more than 120 were dangerous criminals, including members of Tren de Aragua, a Venezuelan street gang designated by the U.S. as a foreign terrorist organization.

The other 50 or so individuals had been held at the base's migrant facility, designed to hold nonviolent individuals.

Hegseth on Tuesday shared photos of his visit to the base on his X social media account, praising U.S. troops there for their support of U.S. deportation efforts.

"These warriors are directly supporting the apprehension and deportation of dangerous illegal aliens," he wrote in one post. "We cannot thank them or their families enough."

The commander of U.S. Southern Command, which oversees operations at the naval base at Guantanamo Bay, told lawmakers earlier this month that the base's migrant facility had the capacity to hold about 2,500 nonviolent detainees. Efforts were underway to allow it to house as many as 30,000 nonviolent migrants slated for deportation.

U.S. deportation efforts have sparked criticism from immigration rights groups.

Earlier this month, the American Civil Liberties Union and several other organizations filed a lawsuit against DHS, alleging the detainees held at the Guantanamo Bay prison facility before being deported Thursday had been improperly denied access to lawyers.

DHS dismissed the lawsuit's allegations.