President Biden said Wednesday that Vice President Kamala Harris “speaks for me” as he appointed her to lead a diplomatic effort to slow the migrant surge at the US-Mexico border.

“I think the best thing to do is put someone who, when he or she speaks, they don’t have to wonder about, ‘Is that where the president is?’ When she speaks, she speaks for me, doesn’t have to check with me. She knows what she’s doing,” Biden said at a White House event.

Biden, 78, this month accidentally referred to Harris as “President Harris” — repeating a gaffe he made once before.

Former President Donald Trump last week claimed “there’s something going on” with Biden and that “you wonder whether or not all of the things that he’s signing, whether or not he understands what he’s signing.”

Biden said Wednesday that Harris will be in charge of negotiating with Mexico and Central American countries to stem the flow of illegal migration and to have them accept people who are being deported.

“The surge we’re dealing with now started at the end of the last administration, but it is our responsibility to deal with it humanely and to stop what’s happening,” Biden said.

“And so this increase has been consequential, but the vice president has agreed — among multiple other things I’ve had her leading, and I appreciate it — agreed to lead our diplomatic effort and work with those countries to accept the returnees and enhance migration enforcement at their borders — at their borders. We’re already talking with Mexico about that.”

The crisis is one of the first to impact Biden’s presidency. Critics blame Biden’s border policies and proposed immigration immigration legislation.

Border officials apprehended more than 100,000 people along the US-Mexico border in February, a 28 percent jump from January. And the number is expected to rise further in March.

The Biden administration has allowed all unaccompanied children who illegally cross the US-Mexico border to stay at least temporarily in the country, but claims to expel single adults and some families under a Trump-era COVID-19 policy.

An average of just 13 percent of nearly 13,000 members of families who tried to cross the border illegally were turned back to Mexico last week, according to a report by Axios.

Last month, Biden terminated Trump’s “Remain in Mexico” policy that required Central American asylum seekers to stay in Mexico while US courts reviewed their claims.

Biden halted construction of his predecessor’s Mexico border wall and issued an order affirming the 2012 Deferred Action for Childhood Arrivals program, which gives work permits and protection from deportation to people brought illegally to the US as minors.

On Thursday, the House of Representatives passed bills that would create a path to citizenship for up to half of the estimated illegal immigrants in the US, including farmworkers and children who arrived as minors. Many Republicans said the bills create new “pull” factors for migration.