Geneva, Strong and resilient health systems are the best defense against pandemics and the multiple health threats of the world, said World Health Organization (WHO) Director-General Tedros Adhanom Ghebreyesus.

"The pandemic has highlighted the importance of strong national and sub-national health systems as the foundation of global health security," Tedros said at a virtual press conference on Wednesday, Xinhua news agency reported.

According to Tedros, on current trends, more than five billion people will lack access to essential health services by 2030 -- including the ability to see a health worker, access to essential medicines, and running water in hospitals.

"Gaps like these don't just undermine the health of individuals, families and communities, they also put global security and economic development at risk," he said.

Saying that the world spends around US $7.5 trillion on health each year, almost 10 per cent of global GDP, the WHO chief emphasized that the best investments are in promoting health and preventing disease at the primary health care level.

"Prevention is not only better than cure, it's cheaper, and the smartest thing to do," he said.