By Michael Martina and David Brunnstrom
WASHINGTON, July 17 (Reuters) - U.S. Secretary of State Marco Rubio heads this weekend to meetings of Asia-Pacific countries in Manila, where he is expected to meet with his Chinese counterpart to prepare a possible September summit between Chinese leader Xi Jinping and U.S. President Donald Trump.
Russian Foreign Minister Sergei Lavrov is also expected to be in Manila next week for meetings involving the 11-member Association of Southeast Asian Nations (ASEAN)
along with the Chinese foreign minister, Wang Yi, and ministers from Japan, Australia, Canada and Britain.
The gatherings come at a time of global instability, with the Iran war disrupting global trade and creating economic stress across Asia.
The U.S. State Department said Rubio would leave for Manila on Sunday to attend the ASEAN Post-Ministerial Conference, the East Asia Summit Foreign Ministers' Meeting, and the ASEAN Regional Forum Foreign Ministers' Meeting.
It said Rubio will also meet with senior government officials from Indo-Pacific countries in a trip lasting until next Thursday.
"The Secretary's visit advances a clear U.S. priority: a free and open Indo-Pacific that delivers safety, security, and prosperity for the region and for the American people," a statement said, adding that Rubio would also use the trip to deepen the U.S. partnership with the Philippines.
The U.S. and China have yet to confirm whether their top diplomats will meet during the forum, although it is widely expected and representatives from the two countries have previously done so.
Analysts say a Rubio meeting with Wang Yi is likely to focus on preparations for a second summit this year between Trump and Xi following their last meeting in May. Trump has said Xi will visit the U.S. at the end of September.
Tense U.S.-China relations have stabilized under a temporary trade truce reached by Trump and Xi in October, but deep differences define ties, which many analysts see mired in a new form of Cold War.
SOUTH CHINA SEA, MYANMAR ON THE AGENDA
The forum is also expected to address tensions in the strategic South China Sea, where territory is contested by several regional countries.
Myanmar is another issue after ASEAN foreign ministers last week held informal talks with the country's foreign minister, the first such face-to-face meeting since a 2021 coup that led to ASEAN barring its leaders from its meetings.
The meetings come shortly after the 10th anniversary of a landmark 2016 ruling that invalidated the legal basis of China's sweeping South China Sea claims, a decision Beijing rejects.
Philippine Foreign Affairs spokesperson Dominic Xavier Imperial said ASEAN and China remained committed to negotiating a "substantive and effective" code of conduct for the waterway and expressed confidence progress could be achieved this year.
Harrison Pretat, a maritime security expert at Washington's Center for Strategic and International Studies think tank, expects Rubio to reiterate U.S. criticism of China's South China Sea behavior, but in a measured way given the Trump administration's other priorities with China.
"He will also not want that to completely derail his talks with Wang Yi," he said, "so I would expect a calibrated approach rather than an attempt to really hammer Beijing. I think China will likewise want to state their position and move on to other things — but there is always room to be surprised."
Another CSIS Southeast Asia expert, Andreyka Natalegawa, said a likely focus would be Southeast Asian scam centers, which the Trump administration says are costing Americans billions of dollars a year.
(Reporting by Michael Martina and David Brunnstrom in Washington and Karen Lema in Manila; Editing by Edwina Gibbs)
