HELSINKI, Finland — U.S. Secretary of State Hillary Rodham Clinton said Wednesday she has “great hope” that an upcoming Geneva meeting of world powers can be a turning point in the Syria crisis. Clinton said the U.S. supports UN envoy Kofi Annan’s plan for political transition in Syria.

Annan “has developed his own very concrete road map for political transition” from the Assad regime, Clinton said at a news conference at the start of her three-country European tour. “We believe it embodies the principles needed for any political transition in Syria that could lead to a peaceful, democratic and representative outcome reflecting the will of the Syrian people.”

The violence in Syria has worsened since a cease-fire deal in April, and the bloodshed appears to be taking on more dangerous, sectarian overtones, the UN said Wednesday. The UN’s deputy envoy for Syria, Jean-Marie Guehenno, told the UN Human Rights Council that the violence in Syria has “reached or even surpassed” levels seen before the April 12 ceasefire agreement and that Annan’s six-point peace plan “is clearly not being implemented.”

Reflecting the sense of urgency, Annan has summoned permanent members of the UN Security Council for a conference on Syria in Geneva on Saturday but has not invited Iran or Saudi Arabia, two of the biggest regional players. Annan’s announcement cited invitations to the five veto-wielding council members — Britain, China, France, Russia and the United States — plus Turkey. Clinton spokesman Philippe Reines said Clinton plans to attend the meeting.

Clinton said she has “great hope” the Geneva meeting can be “a turning point” for the Syria conflict if Russia and China agree to support the Annan plan.

Syrian President Bashar Assad “has relied on the support of Russia and China in the Security Council to prevent the international community from taking unified action,” Clinton said.

“If Kofi Annan is able to lay down a political transition road map that is endorsed by countries including Russia and China, for example, that sends a very different message,” Clinton said. “That’s the first time the international community will have really evidenced a direction that I think Assad will have to respond to.”

Russia, which along with China has twice protected Assad’s regime from UN sanctions and continued to provide it weapons, has argued that the West should raise pressure on the Syrian opposition to sit down for talks with the government. Moscow has argued that the Syrians themselves must determine the country’s future and warned that it would firmly oppose any document urging Assad to step down.