Saudi Arabia and other Gulf countries, including the United Arab Emirates, Bahrain, Qatar, Oman and Kuwait all expressed solidarity with the king.
AMMAN: Jordan announced on Sunday that it had averted a plot against the kingdom involving a half-brother of ruling King Abdullah II, arresting close to 16 suspects accused of "sedition" and alleging foreign complicity.
Prince Hamzah said in a video recording he was under house arrest and had been told to stay at home and not contact anyone.
In a video the BBC said it obtained from his lawyer, Prince Hamzah said several of his friends had been arrested, his security detail removed and his internet and phone lines cut.
He denied being part of "any conspiracy or nefarious organization", but said that the country of 10 million people had "become stymied in corruption, in nepotism and in misrule" and that nobody was allowed to criticize the authorities. He added that the move was part of joint investigations undertaken by security agencies, as a result of which Hasan Bin Zeid, a member of the royal family, along with several others, including Bassem Awadallah, a former cabinet minister, were arrested.
He said: "The investigations had monitored interferences and communications with foreign parties over the right timing to destabilise Jordan".
Safadi did not provide specifics on the alleged plot or say what other countries were purported to have been involved.
Safadi said Hamzah had engaged in "recent activities and movements" that aimed to incite people against the state.
Hamzah's mother, Noor, weighed in on Twitter, writing Sunday: "Praying that truth and justice will prevail for all the innocent victims of this wicked slander".
Abdullah and Hamzah are both sons of the late King Hussein, who remains a beloved figure two decades after his death.
Hamzah denied the accusations against him in a footage published online. "And I will always be supportive and helpful to His Majesty the King and his Crown Prince".
"There is certainly resentment on his part, because he has never digested losing his title of crown prince". Prince Hamzah, the army's chief of staff said on Saturday, had not been arrested but was asked to limit his movements.
Sunday's briefing capped a dramatic moment, but it brought little clarity to what exactly transpired over the weekend when security services arrested nearly 20 people, including high-ranking government officials and a relative of the royal family.
Jordan's estranged Prince Hamzah, in a voice recording released on Monday, said that he would disobey orders by the army not to communicate with outside world after he was put under house arrest. "King Abdullah is a key partner of the United States, and he has our full support". He was also an adviser to Saudi Crown Prince Mohammed bin Salman.
Israeli Defence Minister Benny Gantz called Jordan a "strategic ally" and dismissed the turmoil as an "internal Jordanian matter". "We need to do everything necessary to maintain that alliance".
Awadallah, a US-educated former finance and planning minister, was close to the king but has also been a controversial figure in Jordan.
Awadallah, a proponent of economic reforms, resigned as chief of the royal court in 2008 amid allegations of interference in sensitive political and economic issues.
The interests of the homeland must remain above all considerations, and we must all stand behind His Majesty the King in his efforts to protect Jordan and its national interests, and to achieve the best for the Jordanian people, in commitment to the legacy of the Hashemites who have pledged themselves to serve the nation, and to rally around the dean of the family and the leader of the homeland, may God preserve him.
It declared independence in 1946.
But Barah Mikail, an academic at Saint Louis University Madrid and director of consulting firm Stractegia, said the country "would come off well in the face of a plot hatched against it, particularly as the kingdom's anniversary approaches".