Donald Trump got his first classified briefing in New York City Wednesday after saying that he doesn't really trust American intelligence, and amid weakening poll numbers he is shaking up his campaign. Grace Rauh has the story.

Donald Trump pulled into the FBI building in lower Manhattan Wednesday afternoon to be briefed on emerging and existing security threats around the globe. But even before stepping inside he was raising questions about the intelligence he was set to receive. He said he did not trust it.

"Not so much from the people that have been doing it for our country," Trump told Fox News. "I mean, look what's happened over the last 10 years. I mean, it's been catastrophic."

It is customary for presidential nominees to get classified briefings in the run-up to the general election. But some Trump critics have argued that he is not qualified to get the intelligence. They point to his call for Russia to hack into Hillary Clinton's emails as a sign he cannot be trusted. Clinton critics have said her use of a personal email server at the state department shows she too cannot handle classified information.

Trump also huddled with advisors at Trump Tower for a meeting on Islamic terrorism. Long Island Congressman Peter King and former Mayor Rudy Giuliani were in attendance.

"This is something that needs leadership from a president like Donald Trump," said Giuliani. "This is something that has to come from the top."

The focus on national security comes amid a shakeup in Trump's campaign.

Stephen Bannon, a top executive at the conservative website, Breitbart News, is going to be the campaign's chief executive. And Republican pollster Kellyanne Conway will be the campaign manager.

The changes are demotion for Paul Manafort, Trump's campaign chairman. He has come under fire recently for his work with a pro-Russian party in Ukraine.

As for Trump's briefing, he spent about two hours inside the FBI building. He said nothing on his way in or out.