A Jordanian government spokesman has said the “evil” of Islamic State “can and should be defeated”.
The remarks came amid condemnation from around the Arab world over the killing of a Jordanian pilot by Islamic State.
King Abdullah II cut short a trip to the US after IS posted a video appearing to show pilot Moaz al-Kasasbeh being burned alive.
Jordan executed two convicts, including failed female suicide bomber Sajida al-Rishawi, in response.
Lt Kasasbeh was seized after crashing during a bombing mission by the US-led coalition over Syria in December.
Jordan had sought to secure Lt Kasasbeh’s release in a swap involving Rishawi, but IS is believed to have killed him a month ago.
The BBC’s Paul Adams in Amman says talk of an exchange appears to have been a IS tactic to string Jordan along and foster doubt among Jordanians over its role in the US-led coalition.
Speaking before he left the US, King Abdullah hailed Lt Kasasbeh as a hero, saying Jordan must “stand united” in the face of hardship.
‘Undermine and degrade’
The king was greeted by a crowd of several thousand people at Jordan’s main airport, with many holding up pictures of the monarch, the pilot and the country’s flag in a show of support.
He then held a meeting with security chiefs.
Government spokesman Mohamed al-Momani said a collaborative effort was needed between members of the US-led coalition to “undermine, degrade and eventually finish [Islamic State]”.
“This evil can and should be defeated,” he said, adding that Jordan was “more determined than ever” to fight the militant group.