US Secretary of State Marco Rubio said the decision to suspend visitor visas for Gazans, even those seeking medical treatment after being injured in Israel's war on the enclave, was made after inquiries from members of Congress.
Mr Rubio told CBS on Sunday that the State Department was warned by lawmakers that some of the non-government organisations assisting Gazans with the visas had connections to Hamas.

"We won't be in partnership with groups that have links or sympathy to Hamas," he said when asked about the abrupt decision to halt the visas.
Mr Rubio was also asked about many of the children in Gaza who received visas to undergo urgent medical treatment. "A small number are issued with children, but they come with adults," he said, suggesting he had concerns about Palestinians who accompanied the injured children.
He repeated his belief that evidence presented to the State Department prompted the decision to halt the visas on Saturday morning. "All visitor visas for individuals from Gaza are being stopped while we conduct a full and thorough review of the process and procedures used to issue a small number of temporary medical-humanitarian visas in recent days," the State Department posted on X.
Washington faced swift backlash after announcing the decision. Among the groups to criticise the American authorities was HEAL Palestine, a US registered non-profit group that aims to provide "urgent relief and long-term support to Palestinian children and families". It said it was "distressed by the State Department's decision".
Another prominent organisation, the Palestine Children's Relief Fund, said the move "will have a devastating and irreversible impact on our ability to bring injured and critically ill children from Gaza to the United States for life-saving medical treatment". The group urged the US to reverse its decision.
Shortly after Mr Rubio's interview with CBS, Jason Crow, a Democratic member of the House of Representatives, said claims that some NGOs had links to Hamas "concerning".
"Hamas is a brutal terrorist organisation, they should not be travelling anywhere and if that's happening it should be stopped immediately," he added.
Some speculated that the State Department's decision was motivated by criticism from Laura Loomer, a far-right activist with close ties to President Donald Trump. Ms Loomer decried the visa system and called on Washington to "shut this abomination down".
She said Gazans who arrived in the US were "pro-Hamas ... affiliated with the Muslim Brotherhood", without providing any evidence.
She criticised HEAL Palestine specifically. "This is a medical treatment programme, not a refugee resettlement programme," HEAL Palestine's said in response. "Our mission gives children a renewed chance at life, whether through life-saving surgery or the ability to walk again ... US taxpayers do not fund this treatment."
Israel's ongoing campaign in Gaza – which followed the 2023 attacks by Hamas-led fighters that resulted in the deaths of about 1,200 people and the capture of 240 hostages – has killed more than 61,900 people and injured about 155,800.