Trump Says He Will Close Southern Border Entirely If 'Obstructionist' Democrats Don't Agree to Wall Money

President Donald Trump has threatened to close the U.S. border with Mexico as his impasse with the Democrats over funding for his much-vaunted wall deepens.

In a series of tweets Friday morning, Trump took aim at the Democrats amid the partial government shutdown for hampering his plan to build a wall along the U.S.-Mexico border. Democrats, and some Republicans, have refused to approve his request for $5 billion in additional funds for construction of the wall, and the shutdown is now expected to last until the House Democrats assume the majority next week.

If funding for the wall is not approved, Trump threatened on Twitter to close the border, withdraw from the North American Free Trade Agreement, or NAFTA, and cut off foreign aid to three Central American countries.

Read more: Lindsey Graham claims wall is defense against 'radical Islam'

"We will be forced to close the southern Border entirely if the Obstructionist Democrats do not give us the money to finish the Wall & also change the ridiculous immigration laws that our Country is saddled with. Hard to believe there was a Congress and President who would approve!" Trump tweeted.

The president then lambasted NAFTA, saying that under its rules, the U.S. "looses sooo much money." He claimed the amount was more than $75 billion, tweeting, "I would consider closing the Southern border a 'profit making operation.'"

The 25-year-old agreement was recently renegotiated as the United States-Mexico-Canada Agreement, or USMCA, which awaits ratification by Congress. In an attempt to force Congress's hand, there is a "high probability" that Trump would withdraw the U.S. from NAFTA before the USMCA was ratified, former White House Director of Legislative Affairs Marc Short told the Washington Examiner.

Trump blamed NAFTA for the loss of American companies and jobs, such as those in the automobile industry, and appeared to link the shortcomings of the trade deal to immigration.

"Go back to pre-NAFTA, before so many of our companies and jobs were so foolishly sent to Mexico. Either we build (finish) the Wall or we close the Border," Trump tweeted.

Trump also targeted foreign aid to Central America, tweeting that Guatemala, Honduras and El Salvador "are doing nothing for the United States but taking our money."

"Word is that a new Caravan is forming in Honduras and they are doing nothing about it. We will be cutting off all aid to these 3 countries, taking advantage of U.S. for years!" he said.

The partial shutdown has affected 800,000 federal workers, who have been furloughed or are working without pay. Congress reconvened Thursday but appeared to give up on reaching a deal regarding funding for the border wall before the new year, as no votes are scheduled for Friday or Monday.

South Carolina Senator Lindsey Graham supported Trump's wall on Thursday, claiming it would form part of the U.S. defense against terrorism and part of a global strategy against "radical Islam." Without evidence, he tweeted that the fortifications would be America's "last line of defense" against radical Islamists.

This article has been updated to include Trump's latest tweet about Guatemala, El Salvador and Honduras.