Jordan's King Abdullah received a phone call from Syrian President Bashar al-Assad, the royal palace said on Sunday in what officials said was the first such communication since the start of the conflict in Syria a decade ago.
The conversation was the latest step in a recent normalisation of ties between leaders who had long been on opposing sides in Syria's civil war, with Jordan supporting Syrian Western-backed mainstream rebels seeking to drive Assad from power.
"They discussed relations between the two brotherly countries and ways of enhancing cooperation," the Jordanian palace statement said.
King Abdullah told Assad his country supported the territorial integrity of its northern neighbour and efforts to preserve its "stability and sovereignty", the palace statement said.
The king had called for Assad to step down after the Syrian leader's crackdown on peaceful pro-democracy protests at the start of the conflict in 2011 and Jordan became a conduit for Western and Arab weapon supplies to forces trying to oust Assad.
The staunch US ally has, however, in the last few months accelerated steps to normalise ties with Syria and nearly two weeks ago received the Syrian defence minister in a rare visit to coordinate cross-border security.
Amman also last week fully reopened a border crossing with Syria to boost investment and trade and said it would resume direct flights to Syria by its state owned carrier Royal Jordanian for the first since they were suspended shortly after the outset of the conflict.