Sen. Bill CassidyBill CassidySunday shows preview: Democrats declare victory on COVID-19 stimulus; Vaccination efforts provide hope for summerEnergy Department announces million toward carbon capture, industrial assessment centersBottom lineMORE (R-La.) on Sunday blamed President BidenJoe BidenPompeo: Reentering Iran deal would make Middle East ‘less secure’DNC gears up for midterm pushBiden struggles to unravel web of Trump immigration rulesMORE for a surge of migrants including unaccompanied children at the southern border.

Speaking on “Fox News Sunday,” Cassidy argued that the Biden administration signaled to migrants that the border was open, despite comments from top officials claiming otherwise.

Asked by host Chris WallaceChristopher (Chris) WallaceWallace: Kudlow ‘seems to have found religion’ on government spendingArkansas governor: Removal of coronavirus restrictions an ‘off-ramp’Warner: White House should ‘keep open additional sanctions’ against Saudi crown princeMORE how much blame Biden deserves for the recent surge in apprehensions and border crossings, Cassidy responded: “Empirically, it’s entirely.”

“When people think they can get in, they begin sending their unaccompanied child across Mexico, where she may be kidnapped and trafficked,” Cassidy said, adding that immigration officials were telling migrants in Spanish that the border was “open.”

“There can be no equivocations when it comes to someone who is thinking of joining a caravan [bound for the U.S.],” he added.

The U.S. saw a 61 percent spike in the number of unaccompanied minors apprehended at the border in February compared to a month earlier. A CNN investigation found that thousands of young children are being held in temporary shelters long after they were legally required to be transported to permanent setting while their cases are resolved.

“[W]e continue to struggle with the number of individuals in our custody, especially given the pandemic,” a top Customs and Border Patrol officials said this month.

Democrats in Congress are discussing an immigration package that some have said will attempt to address longstanding conditions across Central America blamed for driving migration from those areas.

Republicans, meanwhile, have hammered Biden on the issue and argued that the president’s ending of policies such as former President TrumpDonald TrumpPompeo: Reentering Iran deal would make Middle East ‘less secure’DNC gears up for midterm pushBiden struggles to unravel web of Trump immigration rulesMORE’s “Remain in Mexico” policy, which required immigrants to wait in Mexico while their asylum cases are resolved, have driven the surge.