WASHINGTON -- The United States is "actively supporting" Israel's defense against what Washington assesses to be an imminent ballistic missile attack from Iran, the White House said Tuesday.

"The United States has indications that Iran is preparing to imminently launch a ballistic missile attack against Israel," multiple US media outlets quoted a senior White House official as saying.

"We are actively supporting defensive preparations to defend Israel against this attack. A direct military attack from Iran against Israel will carry severe consequences for Iran," the official said.

Also on Tuesday, the US embassy in Israel, which is located in Jerusalem, put out a security alert saying it has directed "all US government employees and their family members to shelter in place until further notice." The direction is sent to relevant US personnel in Israel, the West Bank and Gaza.