PALM BEACH, Fla. -- President Donald Trump on Sunday defended his decision to sign a $1.3 trillion federal spending bill despite his misgivings, pointing to billions in new funding for the military and national security.

Trump said on Twitter from his Mar-a-Lago estate in Florida that because of the military funding, "many jobs are created and our Military is again rich." He said building his signature border wall "is all about National Defence."

Since grudgingly signing the bill on Friday after threatening a veto, Trump has faced fierce criticism from conservatives who have accused him of caving to congressional Democrats. The president said Friday at the White House he was "very disappointed" in the package, in part because it didn't fully pay for his border wall. But Trump said he had "no choice" because the nation needed to fund the military.

Trump sought $25 billion for his border wall, but the plan included much less -- $1.6 billion for building new sections of wall and replacing older sections. Trump tweeted Sunday that much can be done with the money and it's "just a down payment."

He said the "rest of the money will come" and again reiterated that Democrats "abandoned" young immigrants seeking protections. Trump on Friday noted that the bill failed to extend protection from deportation to some 700,000 "Dreamer" immigrants due to lose coverage under a program the president himself has tried to eliminate.

Trump's veto threat had put him at odds with top members of his administration and Republican House Speaker Paul Ryan, who urged him to sign the bill. But prominent conservatives have criticized the massive spending plan, warning that it could add to the nation's debt.

The president on Friday warned Congress that he would "never sign another bill like this again." He called for the Senate to overhaul its rules to allow for simple-majority votes on all bills and urged Congress to provide him with a line-item veto power to kill specific spending items he disagrees with. The Supreme Court ruled in 1998 that a congressionally passed line-item veto was unconstitutional.

Because of the $700 & $716 Billion Dollars gotten to rebuild our Military, many jobs are created and our Military is again rich. Building a great Border Wall, with drugs (poison) and enemy combatants pouring into our Country, is all about National Defense. Build WALL through M! — Donald J. Trump (@realDonaldTrump) March 25, 2018