The Trump administration has begun flying undocumented immigrants from the US to a military detention facility at Guantánamo Bay in Cuba, the White House press secretary, Karoline Leavitt, said on Tuesday.

Leavitt told Fox Business Network that at least two deportation flights were “under way”, but gave no further details.

Her comments, however, appeared to confirm reporting by the Wall Street Journal, citing an anonymous official with knowledge of the operation, that about a dozen immigrants were onboard one flight from Fort Bliss, Texas. The newspaper said an additional flight had departed on Monday.

CNN later reported one of the flights had “about nine or 10” people onboard who were detained in the US without valid immigration documents.