Homeland Security Secretary Kristi Noem has said she will recommend a travel ban on several countries which she claims are "flooding" the US with criminal activity.

Writing on social media on Monday, Noem said she had met President Donald Trump and decided to suggest "a full travel ban on every damn country that's been flooding our nation with killers, leeches, and entitlement junkies''.

Trump and the Department of Homeland Security (DHS) then shared Noem's post on their respective official social media accounts.

It is not yet clear which countries the proposed travel ban would impact, or when it could begin. The DHS told the BBC it would announce the list soon.

White House press secretary Karoline Leavitt told Fox News on Monday evening that Trump had announced a travel ban several months ago on "third world and failed state" countries, and that Noem's recommendation would "widen" that to encompass more nations.

On 4 June, the White House listed 19 countries, predominantly in Africa, the Middle East and the Caribbean, which would face full or partial immigration restrictions.

Noem's additions would expand that list to about 30 total countries, multiple US officials told CBS News, the BBC's US partner.

Noem's comments come days after two National Guard members were shot in Washington DC last Wednesday. Prior to her comments about a travel ban, Noem wrote on social media that 100,000 Afghan nationals entered the US under the Biden-era Operation Allies Welcome programme, and she said the DHS would overhaul the vetting process.

Officials identified the suspect in the DC shooting as an Afghan national who entered the US in 2021 as part of that programme, which was designed for locals who had worked with American troops during the 20-year US deployment to Afghanistan.

According to emails from last year that were obtained by CBS News, the suspect struggled with his mental health after arriving in the US.