President Trump on Monday dismissed as "more lies and propaganda" claims out of Iran alleging authorities there had disrupted a CIA spy ring and sentenced several of the plotters to death -- a development that threatened to further inflame an already precarious staredown between the Islamic Republic and the United States.

Trump's tweet, which also mentioned an Iranian drone shot down by the U.S. Navy last week after the unmanned vehicle wandered too close to the USS Boxer, echoed comments made earlier in the morning by Secretary of State Mike Pompeo and cast Tehran as flailing amid tough U.S. sanctions that threatened to strangle its economy.

"The Report of Iran capturing CIA spies is totally false. Zero truth," Trump wrote. "Just more lies and propaganda (like their shot down drone) put out by a Religious Regime that is Badly Failing and has no idea what to do. Their Economy is dead, and will get much worse. Iran is a total mess!

"The identified spies were employed in sensitive and vital private sector centers in the economic, nuclear, infrastructural, military and cyber areas...where they collected classified information," said a ministry statement read on state television.

Pompeo, while not commenting directly on the spy report, advised caution and noted Iran has a history of lying.

"I can’t add much to it specifically," Pompeo told "Fox & Friends" on Monday morning. "I would urge everyone who’s reading that story that the Iranian regime has a long history of lying. They lied about where they shot down the American UAV, they now lied about where they took down this tanker. It’s part of the nature of the Ayatollah to lie to the world. I would take with a significant grain of salt any Iranian assertion of Iranian actions taken. "

Pictures of some of the alleged spies were reportedly shown on state TV, which also broadcast a documentary purporting to show a CIA officer recruiting an Iranian in the United Arab Emirates.

Read more: