PARIS -- The U.S. is set to call for tough United Nations sanctions against President Bashar al-Assad and his inner circle at a "Friends of Syria" meeting of more than 100 Western and Arab nations in Paris on Friday.

Speaking as U.S. Secretary of State Hillary Clinton flew to Paris for the meeting, one U.S. official said it was time "to put this all together under a Security Council resolution that increases the pressure on Assad, including having real consequences," such as economic sanctions.

"We, and we believe most of the countries represented in Paris, think that has to include Chapter 7 economic sanctions on Assad," said the official aboard Clinton's plane who requested anonymity, referring to a clause within the U.N. charter.

Chapter 7 of the U.N. charter, which allows for sanctions ranging from economic measures to an arms embargo, and if necessary military force, was last used against Libya in 2011. But it could be highly controversial at the U.N. Security Council, given Russia and China's veto powers.

The Paris meeting follows a gathering in Tunis and another in Istanbul, both of which called in vain for tougher action against Assad's government.

China didn't attend either of those meetings in which the U.S., France, U.K., Germany as well as Saudi Arabia and Qatar led a group of more than 60 members, including most E.U. states and many Arab League nations.

U.N. Security Council members the United States and France will lead calls at the Paris talks for tough new U.N. sanctions to be imposed on Assad and his inner circle.

French President Francois Hollande will open Friday's talks, which will also be attended by the U.K. and German foreign ministers.