Foreign ministers from the world's leading economies were due to meet for the first time in two years on Monday, after a coronavirus-extended pause.
Britain, which holds the G7 rotating presidency, has billed the event as a chance to reassert to influence of the West and deal with perceived threats from China and Russia.
Who is talking, and about what?
Britain's Foreign Secretary Dominic Raab is hosting his opposite numbers from Canada, France, Germany, Italy, Japan and the US, in London.
The COVID pandemic and climate change are expected to be high on the agenda at the first in-person meeting of foreign ministers since the last one, in France, in April 2019.
Representatives of the European Union are also attending, as well as delegates from Australia, India, South Korea, South Africa and the chairman of the Association of South-East Asian Nations.
"We'll be taking action to ensure fair access to vaccines around the world, setting global girls' education targets, agreeing ambitious action on climate change and developing new measures to prevent famine," said Raab.
The foreign minster said on Twitter that "daily testing and careful safeguards" would be in place to endure "COVID-secure conditions."
Cornwall backdrop to leaders' summit
US Secretary of State Antony Blinken was to met his counterpart Raab bilaterally ahead of the wider gathering in preparation for US President Joe Biden's first scheduled trip since taking office.
On the agenda for the pair — apart from COVID — were the withdrawal of troops from Afghanistan, a post-Brexit trade deal, Iran's nuclear program and China.
The June 11-13 leaders' summit is a chance for Biden to help revive cooperation between allies after years of friction under former US President Donald Trump.
The UK is staging the event in the picturesque seaside county of Cornwall on the southwestern tip of England, in the coastal town of Carbis Bay.
Focus on girls' education
Britain's Foreign Office has said a key part of the June summit will be plans to boost girls' education and women's employment after the COVID-19 pandemic would be a key topic.
The countries are setting up a $15-billion fund, to be administered by developing countries over the next two years.
G7 nations are expected to sign up to new global targets that aim to get 40 million more girls into school in low and lower-middle-income countries by 2026.
The aims also include getting 20 million more girls reading by the age of 10.
rc/msh (AFP, AP, dpa, Reuters)