A vote to leave the European Union would create a "serious threat to global growth", the G7 has officially warned.
The group of global economic leaders said a Brexit would result in a reversal in investment, trade and jobs growth.
The G7 made global growth its priority for the year in tackling economic and security challenges. The leaders pledged to "collectively tackle" threats to the global economy, like terrorist attacks.
In a statement, it committed "to strengthening... policy responses in a cooperative manner and to employing a more forceful and balanced policy mix, in order to swiftly achieve a strong, sustainable and balanced growth pattern".
It added: "We remain committed to ensuring that growth is inclusive and job-rich, benefiting all segments of our societies."
The G7 said it would increase information sharing, as well as improve border control and aviation security.