President Donald Trump threatened to pull out of the North American Free Trade Agreement if Mexico doesn’t stop people and drugs from flowing into the U.S. from Central America.

“They must stop the big drug and people flows, or I will stop their cash cow, NAFTA. Need Wall!” Trump said Sunday on Twitter, minutes before arriving at church for an Easter Sunday service with his wife, Melania.

In a series of tweets, the president also suggested he was no longer willing to strike a deal to assist immigrants brought to the country illegally as minors, and repeated a call for Senate Republicans to go to a simple 51-vote majority as a way to pass legislation more easily.

“Border Patrol Agents are not allowed to properly do their job at the Border because of ridiculous liberal (Democrat) laws like Catch & Release,” Trump wrote. “Getting more dangerous. ‘Caravans’ coming. Republicans must go to Nuclear Option to pass tough laws NOW. NO MORE DACA DEAL!”

The president’s tweet was posted shortly after a segment on Fox News Channel’s “Fox and Friends,” in which Brandon Judd, the president of the National Border Patrol Council, a labor union representing border patrol agents, talked about reports that a caravan of hundreds of Central Americans was headed toward the U.S. in a bid to secure asylum.

‘Havoc and Chaos’

Judd said the immigrants seeking asylum would “create havoc and chaos” while in the U.S. awaiting hearings on their refugee status.

Under current immigration policies, asylum seekers that prove a “credible fear” of returning home may be released while they await adjudication if they don’t present a security or flight risk. Those detained after crossing the border are also sometimes released due to bed shortages and a court ruling that limits the detention of women and children in custody to 21 days.

Trump went on to say those crossing the border “are all trying to take advantage of DACA.”

“They want in on the act!” he wrote.

Under the Deferred Action for Childhood Arrivals program, those eligible for protected status must have lived continuously in the U.S. since 2007 and entered the country before their 16th birthday.

No Bargain

In September the White House rescinded the program, which protected immigrants from deportation. Trump gave lawmakers until March to find a legislative solution for the so-called Dreamer population.

Lawmakers were unable to strike a bargain, with the White House insisting any deal also include new restrictions on legal immigration as well as funding for the president’s border wall. Democrats rejected an offer as part of the omnibus spending package that would have given the president funding for his wall in exchange for a short-term extension of the program. A federal judge in January issued an injunction order keeping the program in place as courts consider legal challenges to the president’s bid to end DACA.

Trump’s declaration that there wouldn’t be a deal on DACA comes even as he’s looked to pin blame on Democrats for the failed legislative effort prompted by his decision to shutter the program.

“DACA recipients have been treated extremely badly by the Democrats,” Trump said at a bill signing last week at the White House. “We wanted to include DACA. We wanted to have them in this bill—800,000 people. And actually, it could even be more. And we wanted to include DACA in this bill. The Democrats would not do it. They would not do it.”

Filibuster Hurdle

Trump’s call to eliminate the filibuster, which he blames for elements of his policy agenda stalling in Congress, is the latest in a series of complaints about the restriction. In September, Trump complained “the Senate Filibuster Rule will never allow Republicans to pass even great legislation” because Republicans “will rarely get 60” votes. The month prior, he said Republicans “are just wasting time” if they maintain the filibuster.

Senate Majority Leader Mitch McConnell, a Kentucky Republican, has said repeatedly he wouldn’t move to get rid of the 60-vote threshold.

Trump said Mexico was doing “very little, if not NOTHING” to stop the flow of immigrants across its southern border, and ultimately into the U.S. “They laugh at our dumb immigration laws.”’

Mexican government officials did not immediately respond to requests for comment.

The president gave notice of his intent to renegotiate Nafta in May, and has repeatedly threatened to pull out of the agreement if terms are not renegotiated to his liking. While the move could be blocked by legal challenges and Congress, a successful bid to exit the pact could badly hit Mexico’s economy, which in 2016 sent 73.3 percent of its exports to the U.S.

“Mexico has got to help us at the border,” Trump told reporters as he entered the Bethesda-by-the-Sea Episcopal Church in Palm Beach, Florida. “If they’re not going to help us at the border it’s a very sad thing.”