Theresa May will travel to the G20 summit in China for her first international conference since she became prime minister.
In her talks with other world leaders she is anticipated to tell them the UK is “open for business” following the referendum vote to leave the EU.
Mrs May will have an one-to-one meeting with US President Barack Obama.
Chinese President Xi Jinping will also meet with her but no announcement on the Hinkley Point project is anticipated.
In July it was announced that the government would postpone a decision on whether to build Hinkley Point – the first new UK nuclear plant in 20 years – until the early fall. The French energy giant EDF, with support from state-owned China General Nuclear, had anticipated to assemble the £18bn plant.
Mrs May is expected to have a meeting with President Xi on Monday after the two-day G20 summit, which will be composed of leaders of the 20 major markets of the world.
BBC diplomatic correspondent James Landale said Mrs May’s meeting with President Xi “could prove the most important”.
On Hinkley Point he added: “Her Chinese hosts have invested billions in this and are pushing hard for a positive decision. It is a judgement call that will show how open and dependable Britain really is,” he added.