Protesters hold up pictures of Jordan's King Abdullah and pilot Muath al-Kasaesbeh as they chant slogans during a rally in Amman to show their loyalty to the King and against the Islamic State, February 5, 2015. [Photo/Agencies]

"We're going after them with everything that we have," Judeh said.

US military aircraft joined the mission to provide intelligence, surveillance as well as reconnaissance and targeting support, a US official said, speaking on condition of anonymity.

The official also said the strikes focused on multiple targets around Raqqa.

State television showed a sombre King Abdullah sitting alongside the army chief and senior officials while visiting the Kasaesbeh tribal family in Aya, a village some 100 km (60 miles) south of the capital, Amman.

Thousands of Jordanians flocked to pay their respects. The region's influential tribes form an important pillar of support for the Hashemite monarchy and supply the army and security forces with manpower.

The Jordanian monarch has vowed that the pilot's death, which has stirred nationalist fervour across the country, will bring severe retaliation against Islamic State.