The parents of Otto Warmbier, an American student who died after 17 months in a North Korean prison, hailed on Wednesday new congressional legislation passed in their son's name that calls for further sanctions on Pyongyang.

Flanked by four Democratic and Republican senators, Fred and Cindy Warmbier commended a provision of the broader National Defense Authorization Act, or NDAA, for applying pressure on North Korea to change its behavior.

Fred Warmbier told reporters the bill was "very important to our efforts because it gives us more tools to force the North Koreans to engage on some level."

The event on Capitol Hill came at a time of heightened tensions between Washington and Pyongyang as denuclearization talks begun with a summit last year between President Donald Trump and North Korean leader Kim Jong-un have stalled.

North Korea has conducted a series of weapons tests and resumed personal insults against Trump, with Pyongyang warning it could take an unspecified "new path" if Washington failed to soften its stance before the end of the year.