A mainland-based academic on Monday said President Xi Jinping's trip to Russia to meet his Russian counterpart Vladimir Putin and observe last week's Victory Day celebrations was intended to cement already close ties between Moscow and Beijing.

Speaking on RTHK's Hong Kong Today programme, Josef Gregory Mahoney, a professor of politics and international relations at East China Normal University in Shanghai, said President Xi wanted to show solidarity with Russia.

"I think linking their cooperation in the past, particularly the cooperation in resisting fascism, in the case of the former Soviet Union resisting the fascism of Nazi Germany, and in the case of China, resisting the fascism associated with Japan, which the USSR also supported, that this is something that they want to present."

Professor Mahoney also said China's firm stance in the face of US tariffs had paid off for Beijing.

"I think what we've seen is that China has been able to ensure that its relationships are firm and it stands strong against this aggression from the United States, and it's put the US in a position where it has to actually de-escalate if it wants to move forward."