WASHINGTON — President Trump’s accusations that President Barack Obama spied on him have stirred another tempest in his early months in office.

Mr. Trump offered no evidence to support his claims that Mr. Obama wiretapped his phones and rejected the assertion by the F.B.I. director, James B. Comey, that the wiretapping claim was false, according to Sarah Huckabee Sanders, a White House spokeswoman.

Here is an assessment.

Sean Spicer, White House press secretary, complained of news outlets using anonymous sources that did not produce credible stories

“There’s been a malalignment for so many months and yet not a shred of single truth has actually come that shows any evidence has existed except anonymous source after anonymous source after anonymous source.”

False. The White House has criticized the use of anonymous sources in reporting, yet has offered its own anonymous sources to support claims or policies. Mr. Spicer’s suggestion that articles citing unnamed officials have turned up nothing is wrong.

In recent weeks, Michael T. Flynn resigned as national security adviser after news reports with unnamed sources revealed he had been in contact with Sergey I. Kislyak, Russia’s ambassador to the United States. Similarly, Attorney General Jeff Sessions recused himself from investigations into Russia after journalists found he had also spoken with Mr. Kislyak, based on conversations with anonymous sources.