House Speaker Nancy Pelosi announced the plan to introduce and vote on the resolution "to limit the president's military actions regarding Iran," in a letter to colleagues late Sunday.

The measure, she explained, "reasserts Congress's long-established oversight responsibilities by mandating that if no further congressional action is taken, the administration's military hostilities with regard to Iran cease within 30 days."

Trump last week ordered the shock killing of Qasem Soleimani, the head of Iran's elite Quds Force and one of the country's most influential leaders, who was slain Friday in a US drone strike in Baghdad.

Pelosi said the move put US troops and civilians in danger by "risking a serious escalation of tensions with Iran."

Democrats have complained that Trump took the action without first consulting with the so-called Gang of Eight top lawmakers in Congress, including Pelosi, and have insisted that only Congress can declare war.

"As members of Congress, our first responsibility is to keep the American people safe," Pelosi said in her letter.

"For this reason, we are concerned that the administration took this action without the consultation of Congress and without respect for Congress's war powers granted to it by the Constitution."

Iran has vowed retaliation for Soleimani's death. Trump has escalated his rhetoric in response, and told Congress that his social media posts about Iran should be taken as notification to lawmakers about his actions.

Pelosi said the resolution will be introduced by Elissa Slotkin, a member of Congress from Michigan and a former CIA analyst who served three tours in Iraq.