China’s President Xi Jinping and Russian leader Vladimir Putin will participate in the virtual summit, which will be Putin’s first appearance at an international event.
As Prime Minister Benjamin Netanyahu prepares to visit China, Israel's Western allies advise to proceed with caution.
"China will support Russia while stressing no interference of its internal affairs," prominent Chinese military expert and TV commentator Song Zhongping said.
Former US president Donald Trump blamed US President Joe Biden for the conflict in Russia, and accused him of colluding with China.
China was enraged after Biden referred to Xi Jinping as a "dictator" at a fundraising event on Tuesday.
Biden made the remarks a day after Secretary of State Antony Blinken met Xi on a trip to China that was aimed at easing tensions between the two countries.
There is an expectation Blinken's visit will pave the way for more bilateral meetings in coming months.
The two leaders discussed bilateral relations and deepening economic ties.
Gates stepped down from Microsoft's board in 2020 to focus on philanthropic works related to global health, education and climate change.
Palestinian Authority President Abbas will be visiting China for three days following China's offer to help revive peace talks with Israel.