The US State Department said Wednesday it has designated Ansar Beit Al-Maqdis, the Egypt-based group that has claimed responsibility for a number of attacks on Egyptian security forces and foreign tourists in Sinai and across Egypt, a "foreign terrorist organisation."
The decision means that any assets the group may have under US jurisdiction will be frozen and that Americans are barred from providing the group with any material support.
The State Department said the group is sympathetic to Al-Qaeda but is not a formal affiliate.
Ansar Beit Al-Maqdis was founded in 2011 and has also attacked the Israeli city of Eilat and a Sinai pipeline.
The group also tried to assassinate Egyptian officials and claimed a February bombing of a Sinai tour bus that killed three South Korean tourists.