Trump Vows to Unveil 'Additional Security' After Slamming Court Ruling as 'Disgraceful'

— -- President Trump this afternoon pledged to “keep our country safe” after he had earlier lashed out at a federal appeals court’s decision to uphold a restraining order against his immigration executive order, tweeting it was “a disgraceful decision.”

Referring this morning to a portion of an article written on the national security blog Lawfare, which highlights a statute that the author says the judges failed to cite, Trump tweeted: "LAWFARE: 'Remarkably, in the entire opinion, the panel did not bother even to cite this (the) statute.' A disgraceful decision!"

Benjamin Wittes, who wrote the article and is the editor-in-chief of Lawfare, swiftly responded to Trump's tweet this morning, saying he supports the court's decision and urged the public to read his full blog post.

"You decide whether the POTUS is quoting me in context. Here's the article. For the record, I support the decision," Wittes tweeted, including a link to his article.

Wittes is also a senior fellow in governance studies at the Brookings Institution in Washington, D.C.

Trump answered reporters’ questions on the court’s decision during a joint White House news conference this afternoon with Japanese Prime Minister Shinzo, saying his administration will continue with the legal process and will "no doubt" win the case.

The president also hinted at further national security steps to come next week. "We are going to do whatever's necessary to keep our country safe," he said.

"We'll be doing something very rapidly having to do with additional security for our country. You'll be seeing that sometime next week."

Trump had taken to Twitter Thursday night to echo earlier remarks he had made to reporters outside White House press secretary Sean Spicer’s office that day, saying the court ruling was a “political decision” and he looked forward to pursuing a legal challenge.

A three-judge panel ruled Thursday not to grant a stay that would have reinstated Trump’s controversial executive order to temporarily halt immigration from seven predominantly Muslim countries in the Middle East and Africa and to temporarily shut down America's refugee program.

“We hold that the Government has not shown a likelihood of success on the merits of its appeal, nor has it shown that failure to enter a stay would cause irreparable injury, and we therefore deny its emergency motion for a stay,” the panel, from the U.S. 9th Circuit Court of Appeals in San Francisco, wrote in the decision.

Trump has expressed confidence in his administration's case in reaction to the court ruling, telling reporters they would "win."“It’s a decision that we’ll win, in my opinion, very easily,” the president said Thursday, though it’s unclear for now what path he will take.

The president has apparently not yet discussed the ruling with newly confirmed U.S. Attorney General Jeff Sessions. Trump told reporters he’d be having dinner Thursday night with Secretary of State Rex Tillerson and casino magnate Sheldon Adelson.

ABC News' Julia Jacobo, Jordyn Phelps and David Reiter contributed to this report.