Kim Jong-un said the US must change its attitude to talks by the end of this year if there was to be a third summit with Donald Trump.

The North Korean leader made the comments during a speech on Friday at a session of North Korea's rubber-stamp parliament, which made a slew of personnel changes that bolstered his diplomatic lineup amid deadlocked negotiations with the United States.

His speech came hours after Mr Trump and visiting South Korean President Moon Jae-in met in Washington and agreed on the importance of nuclear talks with North Korea.

"We of course place importance on resolving problems through dialogue and negotiations. But US-style dialogue of unilaterally pushing its demands doesn't fit us, and we have no interest in it," Kim said during the speech.

According to the Korean Central News Agency, he blamed the collapse of his summit with Trump in February on what he described as unilateral demands by the United States, which he said raised questions over whether Washington has genuine willingness to improve relations. But Kim said his personal relationship with the American president remains good and that they could exchange letters at "any time."