Jordan said on Wednesday that Hamas had tried to recruit activists for military training in Syria and Iran to stage possible attacks in Jordan and said it had found new weapons that included Iranian rocket launchers.
Government spokesman Nasser Joudeh told reporters details of the plot were revealed during interrogations of 20 Hamas fighters arrested by security forces last month.
"Hamas was attempting to recruit elements in the Jordanian arena and trying to recruit elements from abroad to send to Syria and Iran to get military training," Joudeh said.
Jordan said last month rocket launchers, detonators and explosives seized from a secret Hamas arms cache in the kingdom had been smuggled from Syria, where the Palestinian group's exiled leadership is based.
Joudeh said authorities were still searching for other arms caches that Hamas had hidden across the country.
"The security forces believe there are more weapons and rocket launchers that have not been uncovered yet ... Among the weapons seized recently were Iranian rocket launchers," he said.
"This poses a major threat to the national security of the country and we will hold those behind this accountable," Joudeh said.
A Hamas leader in Gaza said Jordan's new accusations were fabricated and aimed at raising tension.
"Hamas is sorry that Jordan is dealing (with Hamas) in this manner, making the issue bigger than it is," said Hamas lawmaker Mushir al-Masri.