MANILA — U.S. Secretary of State Marco Rubio said he discussed with Chinese Foreign Minister Wang Yi on Wednesday the need to identify areas of cooperation to lay the groundwork for a "very positive visit" to Washington in September by President Xi Jinping. Meeting with Wang in Manila on the sidelines of a regional gathering led by the Southeast Asian bloc ASEAN, Rubio said both sides had differences, but their job was to manage them and ensure they do not get out of control. "The work we need to do now in September is to identify what those areas are, so that we can lay the groundwork for a very positive visit ... we talked a lot about that," he told reporters. "There are areas of great differences. Both sides will acknowledge that. We'll have to work through those, and I think these differences will exist for the foreseeable future." "We're obviously always going to defend our national interest, and I expect they'll do the same as they define it, but I think there are some areas of potential cooperation," he added. Wang did not speak to media immediately after the meeting and China ha