Defense Minister Tomomi Inada has canceled her planned visit to South Sudan on Saturday due to an allergic reaction to anti-malarial medication, the Defense Ministry said Thursday.

Inada left Japan for the United States early Thursday to meet with U.S. Defense Secretary Ash Carter the same day. She had planned to fly to South Sudan to assess the situation in areas where the Self-Defense Forces are deployed for U.N. peacekeeping operations.

But the defense minister has developed hives in what is believed to be an allergic reaction to anti-malarial medication. The symptoms have eased since she took medicine to treat the allergic reaction, according to ministry officials.

Inada, who is making her first trip to the United States since assuming her post, is expected to hold talks with Carter in Washington and take part in other events in the country as planned.

But she has given up on her planned trip to South Sudan because the medicine she took to treat the allergic reaction may weaken her immune system, the officials said. She will return to Japan on Saturday.

The government is in the process of deciding whether to give expanded assignments under new security legislation to the next batch of SDF troops to be sent to South Sudan in mid-November.

The new duties could include missions to rescue U.N. staff and others under attack, which critics say could expose the SDF troops to additional risks. So far, SDF personnel have been sent to South Sudan to build roads and other infrastructure.

According to the ministry, SDF members take the same anti-malarial medication before going to South Sudan.