The United States is on high alert and preparing for a possible attack by Iran targeting Israeli or American assets in the region after Israel's strike on the Iranian embassy in Syria, a US official said on Friday.

"We're definitely at a high state of vigilance," the official said in confirming a CNN report that said an attack could come in the next week.

Israeli warplanes bombed Iran's embassy in Damascus on Monday in a strike that killed two Revolutionary Guard generals and five other officers and marked a major escalation in Israel's war with its regional adversaries. The Iranian commanders were reportedly involved in operations by armed militant groups Hamas and Hezbollah against Israel.

According to Iran's Islamic Revolutionary Guard Corps, General Mohammad Reza Zahedi who died in the attack was a senior commander in its Quds Force, which is an elite foreign espionage and paramilitary arm.

Iran has said it reserves the right "to take a decisive response." The head of Lebanon's armed group Hezbollah said on Friday that Israel's strike on Iran's consulate marked a "turning point" since October 7, when Palestinian group Hamas launched an attack on Israel that has led to escalating regional tensions.

US President Joe Biden discussed the threat from Iran in a phone call on Thursday with Israeli Prime Minister Benjamin Netanyahu.

"Our teams have been in regular and continuous contact since then. The United States fully supports the defense of Israel against threats from Iran," a senior Biden administration official said.