Arab and Western leaders are scheduled to meet with Syrian opposition leaders in London this week in an attempt to get them to the bargaining table.

A key group in the Syrian opposition, the Syrian National Council, is refusing to attend the next round of formal peace talks scheduled to take place in Geneva next month.

Foreign ministers of 11 nations are trying to lay the groundwork for what is being called the Geneva II conference. The leaders, which include representatives from the United States, Britain, Germany, France, Saudi Arabia and Turkey, are reaffirming their position that any peace process should be political in nature and move away from the current Syrian regime.

U.S. Secretary of State John Kerry sent a strong message to Syrian leader Bashar al-Assad that he would have to step down if he wants peace to come to his country.

“I don’t know anybody who believes the opposition will ever consent to Bashar al-Assad being part of the government,” Kerry said after talks with Arab officials. “He has bombed and gassed people in his country.”

Assad recently told a Lebanese television station he saw no reason why he could not stand for re-election in 2014.

More than 100,000 people have died since the civil war began in 2011.