Chancellor John Healey, Foreign Secretary Ed Miliband and former prime minister Gordon Brown will join him at the summit to help with this work, he said.
He said the UK will also support countries with the transition to renewable energy amid a “climate crisis”, give smaller countries a louder voice on the world stage, and build on work to educate women and girls.
Denis O’Brien, founder of The Repair Campaign, which describes itself as a transatlantic movement for reparatory justice for the Caribbean, said: “The British Government must stop obfuscating and give a full and formal apology now. This would be a significant and symbolic first step towards reparatory justice.
“Tonight’s statement from the Prime Minister was disappointing, and will not quell the demand for an apology from the 15 Caricom countries in advance of the Commonwealth Heads of Government Meeting in Antigua next week.”