The United States is seeking a joint statement with south-east Asian countries on territorial disputes in the South China Sea, Secretary of State John Kerry said Tuesday at a US meeting with leaders of the Association of South-East Asian Nations (ASEAN), according to dpa. "We are working it through," Kerry said early on the second day of the summit, led by US President Barack Obama at a California resort. Tuesday's agenda was to include the unresolved territorial disputes that four ASEAN members have with China over the South China Sea, which has important shipping lanes and potential oil and other natural resources. China claims almost the entire sea, overlapping with territory of several ASEAN nations, and the dispute has overshadowed recent gatherings of the bloc. The most recent meeting of ASEAN defense ministers failed reach a statement on the South China Sea. All 10 members must agree to produce a statement. Leaders arriving for Tuesday's session walked between a US and an ASEAN flag entering the main building at Sunnylands. Countering terrorism was another security issued to be discussed before the end of the summit. Obama, who welcomed the ASEAN leaders late Monday for the talks as part of his administration's broader focus on Asia, Obama described the meeting as a "landmark gathering" that signified "strong and enduring partnership" between the US and the ASEAN countries. He said ASEAN was central to the region's peace and prosperity and referred to increased security cooperation to "meet shared challenges." Obama stressed the need to resolve disputes through "peaceful, legal means." Myanmar's outgoing president, Thein Sein, sent a vice president, after his party suffered an unexpectedly comprehensive defeat in the November elections. Four of the countries attending are part of the Trans-Pacific Partnership trade deal agreed last year, which Obama hopes to shepherd through Congress before he leaves office in January 2017.