FALMOUTH, England—The head of the World Health Organization on Saturday urged China to cooperate with an investigation into the origins of the coronavirus after a summit of Group of Seven leaders discussed the causes of the global Covid-19 pandemic.

Speaking to reporters after participating in parts of the summit by video, Dr. Tedros Adhanom Ghebreyesus, director-general of the WHO, said he hoped there would be better cooperation and transparency when the next phase of the probe into the virus’s origin is under way.

“As you know we will need cooperation from the Chinese side,” he said. “We need transparency to understand or know or find the origin of this virus…after the report was released there were difficulties in the data sharing, especially in the raw data.”

Dr. Tedros said that the preparations for the probe’s next steps were under way and that the issue of the origin of the virus was discussed by G-7 leaders on Saturday. An initial probe into the origins of the coronavirus, which concluded that a lab leak in China was unlikely, was criticized by several governments.

President Biden has ordered a fresh U.S. intelligence inquiry into the origins of the pandemic. U.S. intelligence has focused on two scenarios—whether the pandemic started as a result of human contact with infected animals, or in a laboratory accident. U.S. intelligence agencies are divided on whether there is insufficient evidence currently to prove either one. Several Western leaders have supported a fresh WHO investigation that explores all possible hypotheses.

Separately, the WHO chief urged vaccine makers to waive intellectual-property rights to vaccines and in turn be compensated by rich nations to bolster a lagging global inoculation program. G-7 leaders pledged to donate one billion vaccines to developing nations by the end of 2022.

World leaders gathered in Cornwall, England, for the first day of the G-7 summit on Friday. As they posed for a socially distanced photo on the beach, protesters marched nearby to demand that they focus on tackling climate change. Photo: Leon Neal/Getty Images The Wall Street Journal Interactive Edition

The WHO aims to vaccinate 70% of the world by June 2022 and says it needs 11 billion vaccine doses to do so.

“We need more, and we need them faster,” Dr. Tedros said. Despite the lack of shots, he added that the goal of 70% of the globe to by vaccinated by June next year was still attainable. He said that production capacity could be increased to enable to hit the target.

President Biden and British Prime Minister Boris Johnson used the G-7 summit in England to announce the donation of 500 million and 100 million vaccines, respectively, for the world’s poorest nations. “We don’t expect to get everything from the G-7,” said Dr. Tedros, who added that he would take his appeal to the wider Group of 20 nations.

While the Covid-19 pandemic continues to rage, the G-7 is focusing on what it can do to prevent the next pandemic. The G-7 governments said they would work toward a plan to ensure vaccines and cures for the next pandemic can be deployed in 100 days through better data and technology sharing.

Write to Max Colchester at max.colchester@wsj.com