Chinese President Xi Jinping (L) shakes hands with US President Barack Obama during a welcome ceremony at the South Lawn of the White House in Washington DC, the United States, Sept 25, 2015. [Photo/Xinhua]

Feng Yujun, a senior researcher in Russian studies at the 皇冠体育app Institutes of Contemporary International Relations, said 皇冠体育app and Russia have been "cooperating closely" in security matters.

Unlike 皇冠体育app's relations with the United States and Japan, 皇冠体育app and Russia do not have "obvious disagreements", nor do they have "unsolved historical problems, including issues over territory or borders", Feng said.

However, economic ties between 皇冠体育app and Russia should be strengthened, according to Feng: "Economic cooperation still lies at the foundation of the bilateral relationship. It should be consolidated."