WASHINGTON, June 4 (Reuters) -

U.S. President Joe Biden signed a sweeping new border

measure on Tuesday that would allow authorities to quickly

deport or send back to Mexico migrants caught crossing the

southwestern border if the daily number of crossings exceeds

2,500.

Biden took office in 2021 vowing to reverse some of

Republican Donald Trump's restrictive policies but grappled with

record levels of migrants caught crossing illegally, which has

become an issue in the tight rematch against in November's

presidential election.

Some human rights activists and left-leaning immigration

experts were sharply critical of the measure, while Republicans

said it did not go far enough or was too late.

AMY FISCHER, MIGRANT RIGHTS, AMNESTY INTERNATIONAL

"This executive action plays into false narratives about

invasions at the border and advances a policy grounded in white

supremacist ideas at the expense of people in search of safety

in the U.S....This is an utterly shameful move for a country

that once helped draft the Refugee Convention."

UNITED NATIONS SPOKESPERSON FLORENCIA SOTO NINO

"Access to asylum for those in need is paramount and any

person who claims to have a well-founded fear of being

persecuted in their country of origin should have access to safe

territory and have this claim assessed before being subjected to

deportation or removal."

ARIZONA REP. RUBEN GALLEGO, DEMOCRAT

"Today's announcement is a step in the right direction, but

we still have more work to do. We also need to hire more border

patrol agents, fix our broken asylum system, and keep our

communities safe."

US REPUBLICAN PRESIDENTIAL CANDIDATE DONALD TRUMP

"Biden is pretending to finally do something about the

border-but in fact, it's all for show because he knows we have a

debate coming up in 3 weeks."

TEXAS SENATOR TED CRUZ, REPUBLICAN

"He could have stopped this every single day of his

presidency...What the White House is doing today is they're just

playing a political game."

SILKY SHAH, DETENTION WATCH NETWORK

"Biden is using the same legal authority to justify his

order that Trump used in 2017 for the 'Muslim Ban.' We were

outraged then and we are outraged now - particularly as Biden

has completely abandoned the values he once touted of

implementing a 'fair and humane' immigration system that helped

him get elected."