European Union leaders have called for more sanctions against Iran by the end of January, in an effort to increase pressure on Tehran over its nuclear program.
However, the leaders did not make an explicit call for an embargo on Iranian crude oil, which EU diplomats have been discussing this month.
Instead, they called on their foreign ministers to broaden existing sanctions, which include asset freezes and travel bans on those involved in the nuclear work.
EU leaders also called on them to study "additional measures against Iran as a matter of priority and to adopt these measures no later than by its next session," which is scheduled for January 30.
The International Atomic Energy Agency last month released new evidence that backed up international concerns that Iran is seeking the atom bomb.
Tehran says its nuclear program is for peaceful purposes only.