WASHINGTON >> President Donald Trump and James Clapper, the former national intelligence chief, are trading verbal barbs that started after Clapper questioned Trump’s fitness to be in the Oval Office.

Trump tweeted Thursday that Clapper was caught lying to Congress.

Clapper says he simply misspoke a few years ago when he said the U.S. was not collecting Americans’ data. Documents leaked by Edward Snowden later indicated widespread domestic surveillance.

Trump also said Clapper sent him a “beautiful letter.”

Clapper tells CNN that he wrote Trump the night before the election saying he hoped the president would support the intelligence agencies’ practice of speaking “truth to power.”

Clapper says Trump thanked him for the note, then later depicted the intelligence community as Nazis for delivering information about Russian interference in the election.