The Foreign Ministry on Friday told Japanese citizens living in Iraq they must leave the country, issuing its highest level of alert ahead of a possible U.S. attack.

The ministry issued the alert after receiving word that it was becoming increasingly difficult to leave Iraq, with people experiencing delays of up to a day at the borders, ministry spokesman Matahiro Yamaguchi said.

On Jan. 24, the ministry began urging Japanese living in Iraq to leave. It had previously issued an evacuation advisory for areas outside of Baghdad and had also warned people against traveling there.

There are currently 36 Japanese residing in Iraq, 29 of whom are based in the capital, he said.

Two staff members will remain at the Japanese Embassy in Baghdad, but plans are being made to evacuate them soon. The embassy was officially closed in 1991, but two staffers have been assigned there on a rotating basis for the past year.

The alert came as U.N. weapons inspectors prepared to give a crucial report to the Security Council on Iraq's alleged program to build weapons of mass destruction.

The U.S. has threatened to use force to disarm Iraqi leader Saddam Hussein.

Japan's Foreign Ministry has also warned Japanese to be cautious about traveling to Bahrain, Kuwait, and Saudi Arabia.