The World Health Assembly (WHA) has been trimmed from the usual three weeks to just two days.
During his address, Xi looked to strike a contrast between himself and Donald Trump, speaking of global cooperation and worldwide solidarity while mourning those lives lost around the world and calling for increased support for the WHO.
119 of the 194 countries showed support for the resolution.
Under pressure to submit China to a probe, Xi said he supported "the idea of a comprehensive review of the global response to COVID-19 after it is brought under control" - not the causes of the outbreak.
"After the research and development of China's coronavirus vaccine is completed and it is put into use, it will be made a global public good", said Xi, whose country now has five potential vaccines in clinical trials.
Defending his government's strategy against the pandemic, Xi said: "All along, we have acted with openness, transparency and responsibility".
He also urged countries to work with the World Health Organization to tackle the killer infection and give more support to African countries to prevent an outbreak there.
Xi said it would focus on helping Africa and would speed up the construction of disease control and prevention headquarters on the continent.
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In one bright spot, Americans' view of the economy improved in early May even as the novel coronavirus continued to spread. Anti-China rhetoric from the Trump administration is likely to continue into election season, she said.
Washington is also leading a number of countries in demanding that the World Health Organization end its exclusion of Taiwan - considered by Beijing to be part of its territory - and allow it to access its assemblies as an observer.
China's Foreign Ministry spokesman Zhao Lijian elaborated on the country's seeming change of heart about the European Union probe. He claimed he did so because the WHA's proceedings had been shortened due to the virus and said it would restart its campaign to be included later in the year when meetings would be conducted normally.
While many countries with official relations with Beijing are upset at China's initial handling of the coronavirus, the pulling of the vote shows that they are not willing to risk political and economic ties to support Taipei's drive for WHA representation.
Taiwan had said it wanted to share with the world its successful experience at fighting the coronavirus, having only reported 440 cases and seven deaths thanks to early detection and prevention work.
Beijing, however relented on its opposition for an inquiry into the origin of the virus.
Geng Shuang, the spokesperson of the Chinese Ministry of Foreign Affairs, praised the World Health Organization and its chief for being "objective, just and scientific in fulfilling its duty".
US President Donald Trump announced last month that Washington, the WHO's largest donor, would suspend its funding to the organisation.
"WHO had determined that the information provided by Taiwan held no value, and it neglected to respond", Taiwanese health minister Chen Shih-chung said last week.