King Abdullah of Jordan says the kingdom is ready to fight to protect itself against any threat to its security from the escalating conflict in neighbouring Syria.
"If the world does not help as it should, and if the matter becomes a danger to our country, we are able at any moment to take the measures to protect the country and the interest of our people," King Abdullah told military cadets at a graduation ceremony in southern Jordan.
Jordanian and US forces are holding two weeks of military exercises 120 km from the Syrian border, with the participation of 17 other countries.
Jordan has taken in more than 500,000 refugees from Syria. It also supports the Syrian opposition and has channelled some arms to moderate rebel groups battling Assad's forces in southern Syria.
The United States has stationed Patriot batteries - an air and missile defence system - in Jordan.