Prime Minister Theresa May met President Recep Tayyip Erdogan of Turkey.
A Downing Street spokesperson said:
This afternoon at the G20 in Argentina, the Prime Minister had discussions with President Erdogan of Turkey.
The leaders agreed that the relationship between the UK and Turkey continues to strengthen.
They discussed modern slavery and agreed it was important to work together globally to stop this awful crime.
The Prime Minister and President Erdogan also discussed the developing trade relationship between the two countries, and agreed there will be opportunity to strengthen this still further when the UK leaves the European Union.
They discussed increasing our defence industry co-operation, in particular through the TFX fighter jet project.
The PM stressed the importance of ensuring that those responsible for the appalling murder of Jamal Khashoggi are held to account, and said that Saudi Arabia should take action to build confidence that such a deplorable incident could not happen again.