HAMBURG (REUTERS) - Japan, the United States and South Korea agreed on Thursday (July 6) to push for China to play a larger role in reining in North Korea's nuclear ambitions, a Japanese official said on the eve of a summit of the Group of 20 economic powers.

North Korea's launch this week of what it said was a nuclear-capable intercontinental ballistic missile dramatically raised the stakes in the long-running battle to contain the isolated country's nuclear weapons programme.

"North Korea now constitutes a new level of threat to Japan and a clear provocation to Japan and also to the international community," said Norio Maruyama, Japanese foreign ministry spokesman, after a meeting of the three countries' leaders.

Japanese Prime Minister Shinzo Abe, US President Donald Trump and South Korean President Moon Jae-In agreed at the meeting to cooperate closely to encourage China to "play an even greater role" in containing its southern neighbour.

"We had very vivid conversation on the subject and the role of China was very important" during the 75-minute meeting, Maruyama said, adding that Japan was closely monitoring Chinese companies it suspected of having links to North Korea's weapons programme.

"Abe conveyed Japan's appreciation for the sanctions the US decided to impose on Chinese organisations," he said.

"The Japanese government has been monitoring the movements of Chinese companies with deep ties to North Korea and responding appropriately" by imposing asset freezes.

Asked whether any military action was discussed, he said:"There is no discussion about the specificity of other measures we could take"