VLADIVOSTOK, Russia (Reuters) - Sharp divisions remain with Moscow over the Syria crisis, U.S. Secretary of State Hillary Clinton said on Sunday, as she wrapped up an Asia tour in which she also made little headway with China on easing tensions in the South China Sea.
Clinton said she had made the case for increasing pressure on Syrian President Bashar al-Assad in talks with Russian President Vladimir Putin and Foreign Minister Sergei Lavrov, but had come away pessimistic about the chances of closing the gap before the U.N. General Assembly this month.
"If we can make progress in New York in the run-up to the U.N. General Assembly, we can certainly try," Clinton told reporters in Vladivostok, where she attended a Pacific Rim summit hosted by the Russian leader.
"But we have to be realistic. We haven't seen eye-to-eye on Syria. That may continue. And if it does continue then we will work with like-minded states to support the Syrian opposition to hasten the day when Assad falls."
On her 11-day Asia trip, Clinton sought to push for more forceful international steps on Syria, greater unity over Iran's nuclear programme and a multilateral mechanism for China to deal with maritime territorial disputes with its Southeast Asian neighbours.
But she appeared to gain little traction with either the Chinese and Russian leadership, both of which restated their firm opposition to what they see as U.S. meddling.
"Our U.S. partners prefer measures like threats, increased pressure and new sanctions against both Syria and Iran. We do not agree with this in principle," Russia's Lavrov told reporters after his talks with Clinton on Saturday.
Putin declined to give details of his brief talks with Clinton but said that although they had been had been constructive and useful, they had yielded no agreements.
Clinton said she would continue to work with Lavrov to see if the U.N. Security Council could formally endorse an agreement brokered by former U.N. Syria envoy Kofi Annan which envisages a transitional governing authority for Syria.
But she added that such a step would only be effective if it carried specific penalties if Assad fails to comply - something Russia has repeatedly resisted.
"There's no point passing a resolution with no teeth because we've seen time and time again that Assad will ignore it and keep attacking his own people," Clinton said.
When the agreement Russia wants the Security Council to endorse was reached in late June, it left open the question of what part Assad might play in a Syrian political process. Russia says his exit must not be a precondition forced from outside.
Clinton's uphill struggle in Vladivostok capped more than a week of arduous diplomacy which took her first to the tiny Pacific state of the Cook Islands and also featured stops in Indonesia, East Timor and Brunei.
She also visited Beijing, which has joined Russia in blocking U.S.-led efforts to rally a strong response to Syria at the United Nations, and engaged in an increasingly angry war of words with some of its neighbours in Southeast Asia over disputed shoals and islets in the South China Sea.
The South China Sea frictions echo similar tensions between China and Japan over the uninhabited Diaoyu islands - called Senkaku in Japan - and surrounding fishing areas and potentially rich gas deposits, and both have set Beijing directly at loggerheads with U.S. allies such as Japan and the Philippines.
The United States has repeatedly said that it takes no position on the competing claims of sovereignty in the South China Sea, which command important international trade routes and lie atop potentially huge energy deposits.
But it has sought unsuccessfully to use its diplomatic weight to push China to drop its opposition to a "code of conduct" for the region, which U.S. officials say could reduce tensions in a region analysts call Asia's most dangerous potential military flashpoint.
China, which says it has historical claim to a huge swathe of the South and East China Seas and would rather deal with each of the less powerful claimants individually, showed no sign of backing down following Clinton's trip.
"Regarding the South China Sea, the position of the Chinese government has been consistent and clear cut. China has sovereignty over the islands in the South China Sea and their adjacent waters," Chinese Foreign Minister Yang Jieche told reporters after his talks with Clinton.
Clinton used her Beijing visit to stress the breadth and depth of the Sino-U.S. relationship, saying it was both strong and important enough to withstand differences on individual issues.
But Chinese state media kept up criticism of U.S. policy before the visit, suggesting that the United States was seeking to "sow discord" as the Obama administration pivots its attention to the Asia-Pacific following years of entanglement in military operations in Iraq and Afghanistan.
(Editing by Steve Gutterman and Alison Williams)