Updated

Jordanian fighter jets have carried out new air strikes, the military said Thursday, a day after the country's king vowed to wage a "harsh" war against Islamic State militants who control parts of neighboring Syria and Iraq.

The army statement did not say which country was targeted. Jordan is part of a U.S.-led military coalition that has bombed IS targets in both countries since last fall, but until now Jordanian warplanes are only known to have carried out raids in Syria.

King Abdullah II pledged to step up the fight against the IS group after the militants burned a captive Jordanian pilot in a cage and released a video of the killing earlier this week. The images have sent waves of revulsion across the region.

On Thursday, warplanes roared overhead as the king paid a condolence visit to the family of the pilot, Lt. Muath al-Kaseasbeh, in his village in southern Jordan. The king pointed at the planes as he sat next to the pilot's father.

Abdullah has said Jordan's response "will be harsh because this terrorist organization is not only fighting us, but also fighting Islam and its pure values."

In a statement Wednesday, he pledged to hit the militants "hard in the very center of their strongholds."

In Washington, leading members of Congress have called for increased U.S. military assistance to the kingdom. Currently, the United States is providing Jordan with $1 billion annually in economic and military assistance.