Ball is in US court on nukes: Kim Jong-un

Kim Jong-un says he does not plan unilateral steps to denuclearise and is instead awaiting a US response to steps he has already taken, according to a senior Russian official who met the North Korean leader.

Valentina Matvienko, a Kremlin loyalist and speaker of the upper house of Russia's parliament, met the North Korean leader in Pyongyang on Saturday, Russia's RIA news agency reported.

Matvienko said Kim had been polite and diplomatic in his remarks about US President Donald Trump, RIA reported.

She added North Korea needed motivation in order to progress to denuclearisation.

"We share this point of view, we believe that motivation should be created, and the aspiration of the (North) Korean leader, people and country to move toward denuclearisation should be encouraged in every way," Matvienko said.

North Korea's position is clear as they have made two serious steps, showing that their intentions to eliminate nuclear weapons and stop the nuclear programs are serious, she said.

"But reciprocal steps should be made then. It is not possible for the document signed (following the North Korean-US summit in Singapore) to be implemented by one party only.

"... they are of course negotiating with the US side so that there is some movement toward each other, so that the accepted obligations are fulfilled step by step, so that there is understanding that there cannot be any quick decisions there, as it takes patience, demeanour, a long time and the obligations' fulfilment by the other side," Matvienko said.

She also quoted him as saying he hoped for Russian backing in weakening US sanctions on North Korea.