The U.S. is considering using its largest non-nuclear bomb against Iran if President Donald Trump revives the dormant war, CNN reported Thursday.

The military plans to use the GBU-43/B Massive Ordnance Air Blast (MOAB) bomb, nicknamed the "Mother Of All Bombs," to target Iranian energy infrastructure and nuclear sites, the news outlet reported, quoting officials familiar with the matter.

Trump seeks to boost his low approval ratings ahead of November midterm elections, with polls showing the unpopular war in Iran and resulting fuel and other price increases are hurting his Republican Party.

Diplomatic efforts to end the conflict, which erupted with U.S.-Israeli strikes on Iran in February, have stalled since the summer.

But officials doubt the bomb's efficacy if deployed, particularly its ability to destroy suspected underground nuclear sites in the Islamic republic.

"The MOAB is a massive information operations weapon that is effective for large-area clearance but not much else," a source familiar with the plans told CNN.

"It is not designed as a deep penetration warhead."

The U.S. and Israel said the war was necessary to prevent Iran from acquiring nuclear weapons – a goal Tehran has long denied pursuing.

Concerns also exist about potential civilian casualties from such a large weapon.

Washington has in recent weeks dialed back military operations in favor of economic pressure.

Agence France-Presse (AFP) has contacted the Pentagon for comment.

In 2017, the U.S. military in Afghanistan dropped the MOAB to target Daesh hideouts in a complex of tunnels and bunkers, killing more than 90 terrorists.