China and the US signed MoUs on two mutual trust mechanisms, namely a mutual reporting and trust mechanism for major military operations and a code of safe conduct on naval and air military encounters in 2014, making them highlights of their military relationship.

Progress in military relations seems to continue in 2015. According to the two defense ministries, they will have a series of joint exercises in 2015, and China is likely to participate in the US-led Rim of the Pacific multilateral naval exercises for the second time.

China and the US will have more cooperation in combating corruption, though there is no extradition treaty between them, Ruan said.

Chinese Foreign Ministry spokeswoman Hua Chunying also confirmed that Chinese and US working groups attended an APEC meeting on anti-corruption in the Philippines in January and that they will meet again in August.

Chinese and US officials are beginning to prepare for the visit. US Deputy Secretary of State Antony Blinken visited Beijing on Wednesday and voiced his commitment to ensuring a success of Xi's visit.

Xi and Obama met in June 2013 for an informal summit at the Annenberg Retreat, California, where they agreed on building a new type of major-country relationship.

In November 2014, Obama paid a state visit to China after attending an Asia-Pacific Economic Cooperation forum in Beijing. Xi and Obama spent some 10 hours together and both countries announced breakthroughs on climate change and visa facilitation.

Xi's September trip will coincide with the 70th anniversary of the founding of the United Nations. Analysts say Xi and Obama are expected to talk on regional and international issues such as the 70th anniversary of the victory against fascism, cyber security, the Iranian nuclear issue and the situation on the Korean Peninsula.