President Donald Trump spent Saturday golfing and attending the Red Cross Ball at his Mar-a-Lago Club while also pledging to work for peace between Russia and Ukraine and tweeting his displeasure with the "so-called judge" who halted Trump's travel ban.

Saturday was Trump's first full day as president at his "winter White House." Trump arrived at Mar-a-Lago Friday and is scheduled to leave Monday morning.

Across the Intracoastal Waterway in the late afternoon and early evening Saturday, anti-Trump protesters marched along Flagler Drive in West Palm Beach. A smaller group showed its support for Trump along Southern Boulevard just west of Mar-a-Lago.

Trump began Saturday with a tweetstorm after Seattle-based U.S. District Judge James Robart ordered a nationwide hold on Trump's Jan. 27 executive order that halted all refugee admissions for 120 days and imposed a 90-day ban on visits from Iraq, Iran, Syria, Libya, Sudan, Somalia and Yemen.

Related: Thousands of anti-Trump protesters march to Mar-a-Lago

“The opinion of this so-called judge, which essentially takes law-enforcement away from our country, is ridiculous and will be overturned!” Trump tweeted at 8:12 a.m. — his third tweet of the morning on the matter.

Trump resumed tweeting about the ruling late in the day, saying Robart’s decision means “many very bad and dangerous people may be pouring into our country. A terrible decision.”

Related: Inside the lavish Red Cross Ball

Trump left Mar-a-Lago at 9:25 a.m. for an unannounced trip to his Trump International Golf Club near West Palm Beach, where he spent more than four hours. The White House did not reveal who played with the president. Trump played 18 holes with Tiger Woods at the same club in December.

Trump, who has been accused of being too soft on Russian President Vladimir Putin, had what the White House described as a “very good” late-afternoon phone call with Ukrainian President Petro Poroshenko.

Related: In Palm Beach, Trump rips ‘so-called judge’ for halting travel ban

“We will work with Ukraine, Russia, and all other parties involved to help them restore peace along the border,” Trump said, according to a White House readout.

Trump also spoke with Italian Prime Minister Paolo Gentiloni about cooperating on security, counter-terrorism and other issues. Trump, who has called for revamping NATO, “reiterated the U.S. commitment to NATO and emphasized the importance of all NATO allies sharing the monetary burden of defense spending,” the White House said. Trump also agreed to attend the G-7 Summit in Italy in May.

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At 8:45, the president and the first lady arrived at the Red Cross ball, according to a report from the White House media pool. The first couple lined up with other guests at the end of a long line entering the ballroom at Mar-a-Lago.

While they were waiting, Trump was asked whether he was confident he would prevail in the government’s appeal of the court ruling blocking his immigration order

“We’ll win,” he replied. “For the safety of our country, we’ll win.”

Trump today is scheduled to speak on the phone with NATO Secretary General Jens Stoltenberg and New Zealand Prime Minister Bill English. The president will return to his Trump International Golf Club in the evening to watch the Super Bowl.