"The quartet urges the Syrian government to take immediate action to close the offices of Palestinian Islamic Jihad and to prevent the use of its territory by armed groups engaged in terrorist acts," said a statement by the international group read by US State Department spokesman Sean McCormack.
The statement by the international quartet, which is working toward Middle East peace, came two days after a deadly attack in northern Israel claimed by Islamic Jihad.
Islamic Jihad said the bombing was a response to the killing of two of its militants by Israeli troops in the northern West Bank over the weekend, one of whom was the overall commander of the Al-Quds Brigades in the West Bank.
On Thursday three Israeli missiles slammed into a car in the northern Gaza Strip, killing two activists from Jihad's armed wing, the Al Quds Brigades, and six civilians who were just leaving a local mosque after evening prayers.
The quartet's text was adopted after a half-hour teleconference Friday between UN Secretary General Kofi Annan, US Secretary of State Condoleezza Rice, British Foreign Secretary Jack Straw, Russian Foreign Minister Sergei Lavrov, EU foreign policy chief Javier Solana and European External Affairs Commissioner Benita Ferrero-Waldner, the State Department spokesman said.