JOHN YANG:

His latest target? A CNN report that FBI officials refused the White House's request to knock down reports of alleged conversations between Trump associates and Russian intelligence officials during the 2016 campaign.

Before this morning's speech, the president tweeted: "The FBI is totally unable to stop the national security leakers that have permeated our government. Classified information is being given to media that could have a devastating effect on U.S."

This afternoon, the Trump administration's relationship with the White House press corps hit another stumbling block. Several news outlets, including The New York Times, CNN, and The Los Angeles Times, were excluded from an informal, off-camera briefing with Press Secretary Sean Spicer. Conservative news organizations were allowed in.

White House officials offered no immediate explanation.

For the PBS NewsHour, I'm John Yang at CPAC in Oxon Hill, Maryland.