The Group of Seven richest countries will look at a proposal to provide a means to rapidly counter Russian "propaganda" and misinformation, British Foreign Secretary Dominic Raab said.
Mr Raab said the UK was "getting the G7 to come together with a rapid rebuttal mechanism" to counter Russian misinformation, Reuters reported.
He was speaking before a G7 foreign ministers' meeting in London, the first to be held in person for two years.
"So that when we see these lies and propaganda or fake news being put out there, we can … come together to provide a rebuttal and frankly to provide the truth for the people of this country, but also in Russia or China or around the world," Mr Raab said.
British, US and European security officials say Russia and China are trying to sow mistrust across the West, including through disinformation in elections.
Moscow denies it is meddling beyond its borders and says the West is gripped by anti-Russian hysteria.
"It's time to think of why the countries that are sick to the core with propaganda, and which used it more than once to justify armed intervention and toppling of governments … accuse our country of their own sins," Russian Foreign Ministry spokeswoman Maria Zakharova said on social media.
China says the West is a bully and that its leaders have a post-imperial mindset that makes them feel they can act like global policemen.
Britain has identified Russia as the biggest threat to its security, although it regards China as its greatest long-term challenge, militarily, economically and technologically.
Mr Raab will meet US Secretary of State Antony Blinken on Monday, starting a week of diplomacy aimed at reinvigorating the G7's role and protecting against those it considers to be undermining the rules-based international order.
"The scope for intense global co-operation, international co-operation with our American partners and indeed the wider G7, that we're convening this week has never been greater," Mr Raab said.
He said that meeting in person, which was only possible due to strict measures such as daily testing, would make diplomacy much easier.
"You can only do so much by Zoom," Mr Raab said.
The G7 members are Britain, the US, Canada, France, Germany, Italy and Japan. Their combined gross domestic product is about $40 trillion – just less than half of the global economy.
British and US officials have expressed concern in recent months about growing strategic co-operation between Russia, the world's largest country by territory, and China, the world's fastest-growing major economy.
"What matters to us most is that we broaden the international caucus of like-minded countries that stand up for open societies, human rights and democracy, that stand for open trade," Mr Raab said.
He said many of those allies wanted "to know how this pandemic started".
The coronavirus outbreak, which began in China in late 2019, has killed 3.2 million people and cost the world trillions of dollars in lost production.
Mr Raab said some of the barriers between the G7 and other like-minded countries should be broken down so that there could be a broader network of allies standing up for open markets and democracy.
Britain has invited India, Australia and South Korea to attend this week's meeting, from Monday to Wednesday, and the full leaders' summit in June.
Asked whether Britain could seek to join a separate group comprising the US, Japan, Australia and India, Mr Raab said there was no concrete proposal as yet, but the UK was looking at ways to engage more in the Indo-Pacific.