Jordan and other members of the US-led coalition targeting the Islamic State jihadist group are to train fighters belonging to "Syrian tribes", the Jordanian government spokesman said on Monday.

"Jordan and other nations in the coalition and in the region will jointly train... Syrian tribes to fight against the terrorist bands," Mohammad al-Momani said at a news conference.

He did not specify which tribes he was referring to.

The Syrian conflict, which began in March 2011 as a popular uprising but later became a civil war in which more than 215,000 people have been killed, has become even more complex with the rise of jihadist groups such as IS.

"Our duty is to support unarmed Syrian people so they can confront Daesh," Momani said, using an Arabic acronym for the jihadist group.

He also indicated Amman was ready to help train and arm forces in neighbouring Iraq for their "war on terrorism".

"We have expressed our readiness to help Iraq on the issue of training and possibly armaments... to help it win its war on terrorism," Momani said.

"We are also discussing the possibility of helping Kurdish peshmerga forces" in the autonomous region of Iraqi Kurdistan, he added, without elaborating.

Jordan, a member of the international anti-jihadist coalition led by Washington, has intensified its air raids against IS since the jihadists burned alive one of its pilots who crashed in Syria.

IS has exploited the war in Syria and instability in Iraq to seize large swathes of territory in both countries.