David Cameron called for the next wave of international development targets to focus on extreme poverty.
The Prime Minister, in Liberia to attend a UN meeting, also insisted bolstering security and civil structures was crucial, alongside aid measures.
More top news
Read Sadiq Khan's full victory speech, as the Tooting MP promised to be a mayor for "all Londoners".
Former footballer Frank Worthington has denied he is suffering from Alzheimer's - a day after his daughter said he was.
A list of results for London Mayor and the London Assembly