Japan’s defence minister has said Tokyo could shoot down a North Korean rocket if it enters Japanese airspace, according to media reports.
"I am considering giving an order to intercept it," Naoki Tanaka told parliament on Monday. Such an order would be subject to approval by the prime minister, he added.
Two Japanese newspapers, Asahi and Yomiuri, reported on Tuesday that Japan was considering deploying several Aegis-class warships and surface-to-air PAC-3 Patriot missiles to take down the rocket.
Nuclear-armed North Korea says April's long-range rocket launch is to carry a satellite into space, but the plan has prompted scepticism among regional governments.
The US said a launch carrying a satellite could violate Pyongyang's agreement last month to stop nuclear tests, uranium enrichment and long-range missile launches, and scuttle US plans to resume food aid.
The Japanese government said late on Monday that North Korea had informed the International Maritime Organisation of the rocket's scheduled trajectory.
It added that it believed the projectile may pass over part of the Okinawa island chain in the far south of the country.
North Korea's closest ally, China, warned that the launch could jeopardise peace as the two countries met to discuss the matter on Tuesday.
Wu Dawei, the Chinese envoy on North Korea, met Ri Yong-ho, the North's vice foreign minister, in Beijing in the second meeting between China and North Korea in five days.
"The Chinese government at the earliest moment expressed our concerns and worries," Luo Zhaohui, director-general of the foreign ministry's department of Asian affairs told a news briefing, referring to the meeting between Wu and Ri.
|Ri Yong-ho, North's vice foreign minister, has met the Chinese envoy on North Korea in Beijing [AFP]
Luo said China called on "all parties to remain calm and exercise restraint, avoid an escalation of the situation ... and play constructive roles to ease the situation in the peninsula".
North Korea has shown no signs of abandoning the launch.
"The launch of the working satellite is an issue fundamentally different from that of a long-range missile," the North's official Korean Central News Agency said late on Monday.
North Korea said last Friday it would launch the satellite to mark the centenary of the birth of its founder, Kim Il-sung, next month.
In 2009, Pyongyang launched a long-range rocket over Japan in what it said at the time was an attempt to get a satellite into orbit. Tokyo and its allies said they considered it to be a ballistic missile test.
In that launch, the rocket passed over Japanese territory without incident or any attempt to shoot it down.