President Trump threatened to close the southern border on Thursday, accusing Mexico and Central American nations of doing “nothing” as illegal immigration surges.

“Mexico is doing NOTHING to help stop the flow of illegal immigrants to our Country. They are all talk and no action. Likewise, Honduras, Guatemala and El Salvador have taken our money for years, and do Nothing. The Dems don’t care, such BAD laws. May close the Southern Border!” Trump tweeted early Thursday.

The president’s tweets come after U.S. Customs and Border Protection Commissioner Kevin McAleenan said the border was at its “breaking point,” noting there are not enough agents to respond to the flow of illegal immigrants crossing the U.S.-Mexico border.

BORDER HITS 'BREAKING POINT' IN EL PASO, CBP COMMISSIONER SAYS

“That breaking point has arrived this week at our border,” McAleenan said during a visit to the border in El Paso, Texas. “CBP is facing an unprecedented humanitarian and border security crisis all along our Southwest border.”

His agency also tweeted that they saw the highest number of "apprehensions and encounters" in over a decade this week -- over 4,000 in one day: "#CBP saw the highest total of apprehensions and encounters in over a decade on Monday, with 4,000 migrants either apprehended or encountered at ports of entry in a single day. Yesterday, that record was broken again—4,117 in a single day."

Last month, more than 76,000 migrants were detained, marking the highest number of apprehensions in 12 years. That figure includes more than 7,000 unaccompanied children. More than 36,000 migrant families have arrived in the El Paso region in fiscal 2019 with about 2,000 at the same time last year, according to CBP data. The influx has prompted new challenges for Border Patrol agents.

HOUSE DEMS FAIL TO OVERRIDE TRUMP VETO IN FIGHT OVER BORDER EMERGENCY DECLARATION

Meanwhile, the president, whose paramount 2016 campaign promise was to build a wall along the U.S.-Mexico border, declared a national emergency in a bid to free up funding for the barrier along the border. This month, the president issued his first veto on a Democrat-backed measure to cancel the emergency.

On Tuesday, House Democrats failed to override Trump’s veto, allowing Trump to move forward with the issue.

Trump had declared the border emergency under a law that lets him shift budget funds to address dire situations. His plan is to shift an additional $3.6 billion from military construction projects to work on border barriers. Congress voted this year to limit spending on such barriers to less than $1.4 billion, and Democrats accused Trump of ignoring lawmakers' constitutional control over spending.

Fox News' Louis Casiano, Andrew O'Reilly and The Associated Press contributed to this report.