LONDON, May 20 (Reuters) - Britain will work with the World Health Organization (WHO) to develop a "pandemic radar" system to identify new coronavirus variants quickly and track emerging diseases globally to ensure the world is never "caught unawares again".

Prime Minister Boris Johnson announced the plan for a new "Global Pandemic Radar" ahead of a G20 Global Health summit on Friday in Rome, where he will speak.

Johnson's office said it would involve a network of surveillance hubs that could watch out for outbreaks and share data on variants and vaccine resistance.

He is using Britain's presidency of the G7 to highlight the need to be prepared for future pandemics, launching an expert group to examine how the development of vaccines against future diseases can be expedited. read more

"Tackling COVID-19 globally and ensuring we are better prepared for future health threats is an absolute priority for the UK’s G7 presidency," Johnson said.

"The world must never be caught unawares again by a virus spreading among us unchecked. We need to build a system of disease surveillance fit for the 21st century, with real-time data sharing and rapid genomic sequencing and response."

Britain will host a G7 health ministers summit on June 3-4, ahead of an in-person leaders summit in south-west England the following week.

Britain has extensive virus-sequencing capabilities that have come to the fore as coronavirus variants increasingly raise the risk of new waves of infections.

WHO Director-General Tedros Adhanom Ghebreyesus said Britain had "set a strong example for pathogen surveillance and sequencing, as well as vaccine development."

"I am delighted that under PM Johnson, the UK will partner with WHO to contribute to stronger global surveillance and a safer world," he said.

At Friday's summit, leaders of the world's largest economies will adopt a declaration recommending voluntary actions to boost COVID-19 vaccine production, snubbing a push from the United States and other nations on patent waivers, the final text shows.

Drugmakers are also set to announce they will provide large supplies of at-cost COVID-19 vaccines to poor nations this year to try to redress a global imbalance, an EU official said.