The tribunal would preferably be set up somewhere in the Middle East, Sweden's Minister for Home Affairs Mikael Damberg told AFP.

He said he believed a tribunal based closer to the region would have an easier time processing cases and securing convictions than countries such as Sweden and Britain.

"A regional mechanism would be closer to both evidence and witness testimony, which could increase the number of convictions," Damberg said.

Damberg said several countries were looking into the matter, and therefore the Swedish government believed the time was right to host a meeting of experts and state officials to exchange knowledge and gauge whether it would be possible to move forward jointly.

Damberg said the Netherlands, Britain, France and Belgium all planned to attend the Stockholm meeting.

The specific type of crimes the tribunal could pursue would be left up to the attending parties to discuss, and Sweden had actively chosen not to present its own model at this stage, Damberg said.

He conceded that the creation of a tribunal was still far off and the road ahead would be complex.

He noted that normally, a legal mechanism would be developed with the affected country -- but a cooperation with the Syrian regime appeared out of the question.

"Neither Sweden nor any country I've spoken with have any interest in having a collaboration with the Assad regime. That makes the situation more complicated," Damberg said.