EU spokesman Michael Mann said Wednesday the EU plans further sanctions and a source told CNN the EU will impose sanctions against 22 more individuals and eight more countries starting Monday.
The EU's announcement came as an opposition group said Syrian security forces killed 13 people Wednesday in the country, where the United Nations says more than 5,000 people have been killed since demonstrations began in March.
The Local Coordination Committees said nine people were killed in Homs, two in the suburbs of the capital Damascus and one each in Idlib and Aleppo.
The United Nations' ability to impose sanctions or authorize military action has been limited because of the reluctance of Russia and China to support international action against the Syrian government.
Russian Foreign Minister Sergey Lavrov said Wednesday "Western countries" had been trying to remove U.N. restrictions on the use of force against Syria.
"The approach of our Western colleagues is one-sided," Lavrov said. "An attack on Syria will not be approved by the U.N., which leaves the attackers fully responsible for their deeds."
Sanctions unilaterally imposed on Syria by Western countries aren't viewed as legitimate by Russia, Lavrov said.
"Unilateral sanctions are always a derogation of the collective efforts of Syria. ... If someone wants to use the U.N. Security Council, it is necessary to discuss everything there, whether we need sanctions or not ... (and) which methods apart from sanctions to use," he said.
Meanwhile, the Financial Times reported anti-government protesters in suburbs of Damascus warmly embraced Arab League observers Tuesday. But they warned President Bashar Assad's security forces would attack when the observers departed.