G20 summit warned of risks to economy as North Korea test-fires missiles

South Korean President Park Geun-hye (R) walks past Chinese President Xi Jinping during their meeting on the sidelines of the G20 Summit

North Korea fired three ballistic missiles off its east coast on Monday in a defiant reminder of the risks to global security, as world leaders including U.S. President Barack Obama gathered at a G20 summit in China for the second day.

North Korea has tested missiles at sensitive times in the past to draw attention to its military might. But Monday's launch risks embarrassing its main ally Beijing, which has gone to extraordinary lengths to ensure a smooth summit meeting in the eastern Chinese city of Hangzhou.