This will be the first NATO summit since Chicago in 2012, and the first NATO summit in the United Kingdom since Margaret Thatcher welcomed NATO leaders to London in 1990.
President Obama, Chancellor Merkel and President Hollande are expected to attend along with leaders and senior ministers from around 60 other countries.
The summit comes as NATO draws down from its longest ever mission in Afghanistan and against a backdrop of instability in Ukraine. It is an opportunity to ensure that NATO continues to be at the forefront of building stability in an unpredictable world.
During working sessions at the Celtic Manor and more informal events in Cardiff, world leaders will look to address issues which threaten NATO countries’ national security, from fragile states to piracy, from terrorism to cyber attacks.