Under intense pressure not to shut down the government for the second time, president Donald Trump grudgingly accepted a compromise deal forced on him by Democrats, but said he'll now declare a national emergency to fund his border wall with Mexico.

Senate Majority Leader Mitch McConnell (R-KY) confirmed Trump had promised to sign the compromise deal that will provide more than $1 billion for barriers along the southern border with Mexico. Trump, however, will take things one step further, said McConnell.

"He also will be issuing a national emergency declaration at the same time. I indicated to him I'm going to support the national emergency declaration," according to McConnell.

McConnell's announcement will trigger new court battles over the constitutionality and legality of declaring a national emergency, which traditionally means a state of war or a national calamity, on the southern border when there clearly is none.

Democrats have loudly voiced their opposition to declaring a national emergency. This run-around Congress will allow Trump to tap other federal funding sources such as the U.S. Armed Forces and disaster-relief aid to stricken Puerto Rico for money to build his wall. Democrats have threatened to take Trump to court if he does declare a national emergency and McConnell's announcement now makes this threat a certainty.

The announcement came as a surprise and will ignite a fierce backlash from Democrats, civil rights activists and even some Republicans that have broken ranks with Trump over the need for a border wall.

Republicans in the Senate frown on the prospect of a lengthy battle in America's courts over the border wall, fearful this issue will take months or even years before it reaches a resolution. They also know there is no guarantee declaring a national emergency will immediately give Trump the money he needs ($5.7 billion) to build his "beautiful wall" with Mexico.

Trump also has to deal with humiliation of again being beaten and outmaneuvered by the Democrats for the second time in less than a month.

The compromise deal Republicans agreed to -- and which Trump said he will sign -- provides less money for border security than the original bipartisan legislation Trump vetoed in December 2018. Trump's veto triggered the 35 day-long partial government shutdown, which Trump took full responsibility for over national television.

Trump was right when he said he's "unhappy" with the bipartisan agreement to prevent a new government shutdown and finance construction of more barriers along border with Mexico. This deal has set aside only $1.4 billion for border wall security and does not include any funding for Trump's border wall.

The original deal in December 2018 allocated $1.6 billion for border wall security. Trump is demanding $5.7 billion for more than 200 miles of wall along America's border with Mexico.

Right-wing zealots were furious at Trump again caving to Democrats, with one even blasting it as a "garbage compromise." Trump was excoriated by right-wing media hosts and widely criticized by fellow Republicans for not being able to seal a better deal.

The Senate overwhelmingly approved the compromise spending bill on Thursday. The House of Representatives will follow suit. Trump must sign the bill by midnight on Friday to avoid another government shutdown.