WASHINGTON (CBSNewYork) — President Donald Trump began his second full day in office by swearing in his senior staff.

He also took to Twitter, reacting to the millions of people who participated in women’s marches around the world Saturday.

Trump held the swearing in ceremony for 30 assistants to the president in the East Wing of the White House on Sunday. During his remarks, he held up a letter that former President Barack Obama left in the oval office.

“We won’t even tell the press what’s in that letter,” Trump said.

During the administration’s first White House press briefing Saturday, Press Secretary Sean Spicer slammed the media’s coverage of inauguration turnout.

“This was the largest audience to ever witness an inauguration, period,” he insisted.

Although many eye witness accounts say the crowds were not as big as they have been for past inaugurations, official attendance estimates are no longer recorded.

Couselor to the President Kellyanne Conway attempted to clarify Spicer’s claim on Sunday.

“You’re saying it’s a falsehood, and they’re giving Sean Spicer, our press secretary, gave alternative facts to that. But the point remains…” she said in an interview on NBC’s “Meet the Press.”

“Wait a minute — alternative facts?” host Chuck Todd asked.

Senate Minority Leader Chuck Schumner, D-New York, had a message for the president Sunday.

“You’re president now, not campaigning. Stop talking about how many people went to your inauguration and start talking about how many people you’re going to get into the middle class,” he told WCBS 880’s Myles Miller. “President, stick to the presidential issues.”

Earlier, Trump posted dueling tweets on the Women’s March on Washington that exceeded attendance expectations. First tweeting, “watched protests yesterday but was under the impression that we just had an election! Why didn’t these people vote?.”

But later, he shifted his tone, calling the peaceful protests a “hallmark of our democracy.”

The president has a full schedule in the days ahead, meeting with world leaders at the White House.

Aides say Trump spoke with Israeli Prime Minister Benjamin Netanyahu by phone Sunday and discussed ways to advance peace and security in the region. The two also discussed plans to move the U.S. Embassy in Israel from Tel Aviv to Jerusalem.

Netanyahu congratulated the president, saying he values his friendship with Israel and his hard stance against “radical Islamic terror.”

Trump is also scheduled to meet with leaders from Canada and Mexico to discuss NAFTA, and he’ll host British Prime Minister Theresa May later this week.

Meanwhile, the president continues to face resistance from Senate Democrats over some of his cabinet appointments, but veteran Republican Sens. John McCain and Lindsay Graham now say they’re ready to support the president’s pick for Secretary of State Rex Tillerson.