In a Friday tweet, President Donald Trump threatened to shut down all, or most of the southern border next week if Mexico doesn’t act immediately to stop illegal migration into the US in its entirety.

With migrant detention numbers surging past the crisis point in the border-adjacent city of El Paso in Texas this week, Trump is now promising to resort to the swift and drastic measure of shutting down border crossings altogether if Mexico doesn’t take action.

“The DEMOCRATS have given us the weakest immigration laws anywhere in the World. Mexico has the strongest, & they make more than $100 Billion a year on the US,” Trump said, demanding congressional action to beef up security at the border.

The president then demanded that Mexico must also take drastic action to “stop illegals from entering the US” through the southern border, issuing the country an extremely time sensitive ultimatum.

If Mexico doesn’t immediately stop ALL illegal immigration coming into the United States through our Southern Border, I will be CLOSING the Border, or large sections of the Border, next week.

Shortly after issuing the inflammatory tweets, Trump confirmed to reporters that the border shutdown could affect “all trade,” and that he would “keep it closed for a long time.” “I’m not playing games, Mexico has to stop it,” he added.

Asked about the president’s comments, US Customs and Border Protection Deputy Commissioner Robert Perez toldCNN that “the entirety of the immigration system is absolutely overwhelmed,” adding that it was essential to “work with our Mexican counterparts” to handle the issue.

Politicians on both sides of the aisle have been scrambling to point the finger after footage emerged of hundreds of migrants being housed under a bridge in El Paso due to extreme overcrowding in detention facilities. Border Patrol Commissioner Kevin McAleenan announced earlier in the week that the agency had even begun to risk “direct releases” of migrants the government is unable to provide for.

Mexico did not take Trump’s remarks lightly, with the country’s Foreign Minister Marcelo Ebrard taking to Trump’s social media of choice – Twitter – to reject the threats and praise his own country.

“Mexico does not act on the basis of threats. We are a great neighbor. [Ask] the million and a half Americans who chose our country as their home, the largest community of [Americans] outside the US For them we are also the best neighbor they could have,” Ebrard wrote.