A senior South Korean envoy said Wednesday that the door was open to restarting talks with Pyongyang on its nuclear programme, despite US sanctions following a cyberattack linked to North Korea satire "The Interview".

At a meeting in Tokyo on Wednesday, Seoul's top nuclear envoy Hwang Joon-Kook met with his US and Japanese counterparts in a bid to re-open stalled talks on North Korea's nuclear development.

Six-country talks on aid-for-denuclearisation involving Russia, China, North Korea, South Korea, the United States and Japan have been at a standstill since 2009.

"The door of dialogue remains open with respect to the North Korean nuclear issue," Hwang told reporters.

"The United States took measures to pressure the North over the cyberattacks on Sony Pictures Entertainment, but it should not be interpreted as the US closing the door to dialogue."

Washington's North Korea envoy Sung Kim said the three nations agreed to keep urging Pyongyang to commit to denuclearisation.

"The three countries are united in our common pursuit of denuclearisation of North Korea," he said.

The trio also agreed that Pyongyang's recent offer to suspend nuclear tests in exchange for a temporary freeze on US-South Korea joint military exercises should be rejected.

"The US-South Korea joint military exercises are conducted regularly and transparently with the clear nature of defence," Hwang said.

"North Korea's nuclear tests are banned under Security Council resolutions, and we firmly agreed on the position that we should not discuss nuclear tests and the military drills together."

The meeting Wednesday -- which included Japan's Junichi Ihara, envoy for North Korean issues -- came weeks after Washington imposed the financial sanctions on North Korea and several senior government officials.

Washington blamed Pyongyang for a crippling cyberattack on Sony Pictures that saw the release of a trove of embarrassing emails, film scripts and other internal communications, including information about salaries and employee health records.

The hackers -- a group calling itself Guardians of Peace -- issued threats against the US-based company over the planned Christmas release of "The Interview", which depicts a fictional CIA plot to assassinate North Korean leader Kim Jong-un.

Pyongyang has repeatedly denied involvement but strongly condemned the film.