British Prime Minister Boris Johnson will welcome leaders from around the world to the G7 summit in Cornwall today.
What is the G7?
The Group of Seven countries brings together some of the world's richest democracies - the UK, US, Canada, Japan, France, Germany and Italy, along with representatives of the European Union.
Where is the summit happening?
The UK holds the rotating presidency so has responsibility for hosting the summit, which will take place until Sunday at Carbis Bay in Cornwall.
Why is it important?
It is the first time the leaders have met in almost two years, due to the pandemic and the fight against coronavirus will be one of the main items on the agenda.
Boris Johnson has called on his fellow leaders to commit to vaccinating the world against Covid-19 by the end of next year.
What else is on the agenda?
It is Joe Biden's first overseas visit as US President and he will use the visit to try to build an alliance of democracies as a counterweight to China, with the White House saying they expect G7 leaders to announce a new initiative to provide financing for physical, digital and health infrastructure in the developing world as an alternative to the "belt and road" measures offered by Beijing.
The leaders are also expected to discuss issues including climate change and getting more children into education around the world.
Who are the leaders attending the event?
Along with Mr Johnson and Mr Biden, Canada's Justin Trudeau, Japan's Yoshihide Suga, France's Emmanuel Macron, Germany's Angela Merkel and Italy's Mario Draghi will represent their countries.
The European Union will be represented by commission president Ursula von der Leyen and council president Charles Michel.
Australia's prime minister Scott Morrison, South Korean president Moon Jae-in and South African president Cyril Ramaphosa will all attend as guests, while India's Narendra Modi will participate via video link due to the coronavirus crisis.
What are the potential problems facing the Prime Minister?
The summit is an opportunity for Mr Johnson to push his "Global Britain" agenda, placing the UK at the centre of the world stage.
But the days leading up to the summit have seen a damaging row within the Tory party over his decision to cut aid spending from 0.7% of national income to 0.5%, with predecessor Theresa May warning "the damage it does to our reputation means that it will be far harder for us as a country to argue for change" around the world.
Will Brexit be an issue?
Brexit is always an issue. The ongoing row between the UK and European Union over the Northern Ireland Protocol is likely to loom large.
Unusually for a summit of leaders, Brexit Minister David Frost will be in attendance and Mr Johnson will hold talks with European Commission chief Ursula von der Leyen as well as the leaders of France, Germany and Italy.
US President Mr Biden also takes an interest in the issue, with the White House warning against anything that would imperil the Good Friday Agreement.
Are protests expected?
Extinction Rebellion activists have promised a series of demonstrations to call on the G7 to do more to tackle climate change.
The Kill the Bill movement will also protest against Britain's Police, Crime, Sentencing and Courts Bill.
So will security be tight?
Very. Some 5,000 extra officers from around the country have been drafted in to support Devon and Cornwall Police.
In total, 6,500 officers and staff will be deployed in the operation, with 1,000 of them effectively living on a ship moored in Falmouth.