(CNN) — President Donald Trump tweeted Wednesday, without citing any evidence, that the administration has information that "Iran or its proxies are planning a sneak attack on US troops and/or assets in Iraq." Trump added, "If this happens, Iran will pay a very heavy price, indeed!"

The President's tweet, which the White House did not elaborate upon, comes as the US has picked up more intelligence in the last several days from an ongoing stream indicating that Iranian-backed militias inside Iraq are potentially planning an attack against US forces in the near future, one US official said.

The White House did not respond to requests for comment.

The intelligence is some of the latest in a threat stream that the US has been monitoring in Iraq in recent months, the official said. It follows the US killing of Iran's second most powerful official, Gen. Qasem Soleimani, in January, and tit-for-tat strikes between the US and Iraq-based militias in March.

On March 12, US warplanes struck five targets in southern Iraq affiliated with a militia with ties to Iran after a rocket attack the day before killed two Americans and a British soldier. Secretary of Defense Mark Esper the attack was carried out by Iranian-backed Shia militia groups. Soleimani's killing prompted calls for revenge from Iranian officials and affiliated militias in the region.

This newest intelligence includes information gathered from people in the region as well as communications intercepts, the official said. It comes as Iran is reeling from the coronavirus pandemic, which has killed senior officials, sent others into isolation and left health systems overwhelmed by an estimated 47,000 known infections, according to the World Health Organization.

The coronavirus has slowed down much of Iran's planning and it is possible it could still stall any attack, the official said. Since the US killed Soleimani, there has not been a leader of his influence over the militias and the forces he once controlled inside Iraq, adding to uncertainty.

The New York Times has reported that there has been tension within the Trump administration about whether to escalate military action against Iran, with officials such as Secretary of State Mike Pompeo urging a harder response after the March 11 killing of the two Americans.

Pompeo and national security adviser Robert O'Brien have argued that a hard response to Iran while the coronavirus pummels the country would make its leaders more open to negotiating with the US, the Times reported.

But Pentagon officials, including Esper and Chairman of the Joint Chiefs Gen. Mark Milley, have argued against such a move. They have said that they lacked clear evidence the March 11 attack had been ordered by Iran, the Times said. And they've cautioned that a harsher response could give rise to a wider war with Iran and further damage badly strained ties with Iraq, they warned.

In the end, the US conducted its March 12 airstrikes on weapons depots. Since then, the Pentagon has taken steps to improve defenses for its troops stationed in Iraq.

Last month, Gen. Kenneth McKenzie, commander of US Central Command, said for the first time that the US is moving PATRIOT missile systems into Iraq. "We've put the preparatory materiel in place that will allow us to establish PATRIOT positions inside Iraq," McKenzie told reporters at the Pentagon.

The US will be sending the PATRIOTs to bases in Al Asad and Irbil, and will also strengthen both places with counter-artillery and rockets systems. US troops have also consolidated into fewer bases within Iraq.

The US assessment is if there is an attack against US forces, the militias as well as elements of Iran's Revolutionary Guard Corps would likely use a combination of rockets fired from their position inside Iraq and armed drones fired from inside Iran.

The assessment is these weapons would give plausible deniability to the attackers. It's a strategy that differs from Tehran's January 8 attack on the Al Asad base, which is used by American, Iraqi and British forces. That assault, meant to retaliate for Soleimani's January 3 killing, used ballistic missiles unique to Iran.

For the last several weeks, the Pentagon has been refining an extensive package of military options for Trump if a response to Iran is required. As always, the options range from non-kinetic actions, such as potential cyber operations, to a full-scale attack against multiple targets inside Iran.

This story was first published on CNN.com 'Trump threatens heavy price if Iran conducts 'sneak attack' on US troops'