The United States on Thursday restricted movements of its diplomats in "Israel" over security fears, the embassy said, as concerns mount of Iranian retaliation over the Israeli aggression that targeted the Iranian consulate in the Syrian capital Damascus on April 1.

"Out of an abundance of caution, US government employees and their family members are restricted from personal travel" outside the "Tel Aviv", al-Quds, and Beer al-Sabe' areas "until further notice," an embassy notice said.

"The security environment remains complex and can change quickly depending on the political situation and recent events," the notice read.

On April 6, CNN cited a senior Biden administration official as saying that the United States is currently on high alert and actively preparing for a potentially "significant" Iranian attack.

The official mentioned that senior American and Israeli officials believe that an Iranian attack is "inevitable".

According to CNN, both governments are intensely coordinating their efforts to position themselves ahead of the anticipated strike. They anticipate that Iran's response could manifest in various forms, putting both US and Israeli assets and personnel at risk.

The announcement comes as, in recent days, Iranian officials have vowed to retaliate against the Israeli strike that targeted the Iranian consulate, which resulted in the martyrdom of seven advisors from Iran's Islamic Revolution Guard Corps (IRGC).

Iranian leader Sayyed Ali Khamenei underlined Wednesday that "Israel" "must be punished and will be punished."

Earlier on Thursday, White House Press Secretary Karine Jean-Pierre said that the United States has "warned" Iran over its threats to "Israel".

"We warned Iran," Jean-Pierre told reporters in a briefing, a day after US President Joe Biden promised "ironclad" support for "Israel" against any Iranian attack.

"We do not want this conflict to spread. We have been very clear about that. We have made it clear to Iran that we are not involved in the Damascus attack," the White House Press Secretary said.

"We warned Iran against using this attack as a pretext to escalate further in the region or attack our facilities or personnel," she added.

The Pentagon said on Thursday that, General Michael "Erik" Kurilla, the top US commander for the Middle East is in "Israel" for talks on "security threats in the region" with Israeli military officials.

Axios cited Israeli officials as saying that they are preparing for a potential unprecedented direct attack originating from Iranian territory, utilizing ballistic missiles, drones, and cruise missiles against Israeli targets.

According to the officials, "Israel" will strike back with a direct attack against Iran in such an event.

An Israeli official added that, in recent days, "Israel" and the United States have been coordinating "joint air and missile defense" operations in the region in anticipation of a prospective Iranian attack.

Read more: Blinken asks China, others to dissuade Iran from striking 'Israel'