The Prime Minister is expected to use the summit to pile pressure on Vladimir Putin, but also show the UK remains a global force willing to work with friends and partners.
This has already been seen in the new deal with France to address channel crossings, with aides already briefing a reset of relations with Emmanuel Macron.
Given his predecessor was unable even to say if she considered the French president to be a “friend or foe”, such a quick turnaround is remarkable.
Top of the list is Ukraine, with the Prime Minister keen to stress there is no change in policy on the crisis, despite the multiples changes in Downing Street.
Mr Putin was supposed to attend the event in person, but instead sent his foreign minister Sergey Lavrov, who was taken to hospital on arrival with an apparent heart issue.
The Kremlin insist this was made up by Western media, but the problem does make any semblance of talks with Russia more difficult.
So instead, the focus for the Prime Minister will be China, one of the few countries that supports Russia.
Meeting with China’s supreme leader Xi Jinping will give Mr Sunak the chance to not just establish better economic relations, but a more shared stance on Russia.
The Prime Minister has spread nerves among his own party ahead of the meeting, with fears he will soften the UK’s stance towards Beijing for economic purposes.
This would come despite deep divisions between the two Government’s on human rights, Hong Kong, as well as Mr Xi’s interest in invading Taiwan.
There is an expectation the strong lane taken by Liz Truss will be “dialed back”, according to one Government official, who labelled it “continuity Boris”.
Sunak has left open the possibility that he could meet with Mr Xi, stressing he wanted to use the summit to build “strong relations”.
Meeting with the Indonesian leader Joko Widodo is also important, as his country has taken an ambiguous stance on the Ukraine conflict.
Hardening or changing the stances is crucial to the summit, with Britain keen to make Russia even more isolated.
US president Joe Biden is another leader aiming to improve ties with China, and the summit will also see his first meeting with Mr Sunak in person.
He will seek to persuade President Biden that Britain remains a reliable ally on the world stage, and also avoid any rows about how Brexit has affected the Good Friday Agreement.
After a softening of the UK stance at last weeks British-Irish Council, the groundwork has been laid for an attempted rekindling of the once special relationship.
Despite this, the pair have yet to pencil in a one-on-one meeting.
Then there is trade, the great promise of Brexit, with Mr Sunak facing an uphill battle to salvage the deal previously hoped for with India.
Mr Sunak will need to smooth things over with Prime Minister Narendra Modi after a controversial intervention on migration by the Home Secretary Suella Braverman ended talks last month.
Mr Sunak’s government is intent on working closer with its international partners, but there remains damage to be undone.