US National Security Adviser Jake Sullivan has asked China to set aside its issues with India and play a "constructive role" in the upcoming G20 summit. Sullivan said it was up to China if it "wanted to play the role of a spoiler" instead. His remarks come after China confirmed that its leader, Xi Jinping, would not attend the meeting. India will host the summit in the capital Delhi on 9 and 10 September. Neither India nor China has given specific reasons behind Xi"s absence. China has said Premier Li Qiang will lead its delegation at the summit instead. India and China have a frosty relationship and tensions between the two countries have worsened since 2020, when their troops were involved in a deadly clash at the Galwan valley in Ladakh. The source of the tension between the neighbors is a disputed 3,440km (2,100 mile)-long de facto border along the Himalayas - which is poorly demarcated and soldiers on either side come face to face at many points. Last week, the two countries got into a diplomatic row over an "official map" released by China, which India said laid claim to its territory. Beijing responded by saying that Delhi should refrain from "over-interpreting" the issue. Asked by a reporter at a press briefing if tensions between India and China would overshadow the summit, Sullivan said that that was "up to China". "If China wants to come in and play the role of spoiler, of course, that option is available to them," he said. But he added that the summit"s chair - India - the US and "every other member" of the G20 would encourage China to "come in in a constructive way on climate, on multilateral development bank reform, on debt relief, on technology, and set aside the geopolitical questions and really focus on problem-solving and delivering for the developing countries". The G20, or Group of Twenty, is a club of countries that meets to discuss plans for the global economy. Between them, G20 countries account for 85% of the world"s economic output and 75% of world trade. They contain two-thirds of the global population. — BBC