North Korean Scud-B Missile, South Korean Hawk Surface-To-air Missiles
Models of a North Korean Scud-B missile, center, and South Korean Hawk surface-to-air missiles are seen at the Korean War Memorial Museum in Seoul. Reuters

Satellite images show North Korea has likely completed a second long range missile launchpad, an expert said on Thursday, amid U.S. concerns that Pyongyang's ballistic missile programme is fast becoming a direct threat.

The launchpad is more sophisticated than the country's first facility and strikingly similar to a Chinese site, suggesting Beijing's involvement, Tim Brown, an image analyst from military analysis group globalsecurity.org, told Reuters in a telephone interview.

And he said the reclusive North, which says its missile programme is peaceful and intended to put a satellite in orbit, was working on development together with Iran and Pakistan.

The facility at Tongchang-ri is equipped with a 100-ft (30-m) launch tower and is sited near North Korea's northwest border with China, making it more difficult for U.S. intelligence to observe compared to its Musudan-ri launchpad in the east.

The Tongchang-ri site has been under construction for a decade.

Brown, who identified the latest development, said the images were taken about a month ago, and that there were no signs of an imminent test launch. He said it would take weeks, possibly months, to put a rocket on the launchpad.

A South Korean government official also said there were no signs the North was preparing a missile test.

The North is developing the so-called Taepodong-2 missile, with an estimated range of 6,700 km (4,160 miles), but testing so far suggests production of the complete weapon is a long way off.

The North's arsenal already includes intermediate-range missiles that can hit targets up to 3,000 km (1,860 miles) away, officials say, putting all of Japan and U.S. military bases in Guam at risk.

Basically this thing is done, and the question is how long it will be before they launch. Then it is matter of what kind of vehicle are they going to launch -- a missile or something for their space programme. The answer to that is we just don't know, said Brown. A launch, he said, was likely in months.

He said the site was nowhere near the standard of advanced countries. But it's as close as a third world country can come to having a first world facility, he said.

Brown said the facility was very similar in design to a Chinese site being monitored. Either they adopted those design characteristics on their own, or the Chinese were technically advising them and providing assistance.

He said Iran, Pakistan and North Korea were working together on missile and nuclear programmes. We think they all work on different aspects and share and benefit from comparative advantages of each programme, said Brown.

The North Korean site is seen as key to Pyongyang's quest to build a missile capable of delivering a nuclear weapon across the Pacific.

Experts say they do not believe the North can miniaturise an atomic weapon to place on a missile, but it is trying to develop such a warhead. It needs more nuclear testing to build one.

North Korea detonated nuclear devices in 2006 and 2009, and conducted long-range missile tests three times -- in 1998, 2006 and 2009. The missiles fizzled out shortly after takeoff.

While the North still has not shown it has a working nuclear bomb, proliferation experts say it has enough fissile material for up to 10 nuclear weapons.

POLITICAL WEAPON

Washington says the North's long-range ballistic missile programme is moving ahead quickly and Defence Secretary Robert Gates said last month that the American mainland could come under threat within five years.

North Korea has been five years away for the last 15 years, said Brown. They have been on the cusp of having a real missile programme for quite some time.

Brown said that if North Korea can achieve its stated aim of putting a satellite in orbit, it could also launch a missile that hits the U.S. West coast.

At the same time they claim it is their right to launch a peaceful satellite, they also hold out this threat 'don't mess with us,' he said.

Brown added that if the North did launch in a military way, the facility would be quickly be bombed and its long-range programme would no longer exist.

This is a political weapon, not a military weapon, he said. By having this programme they are able to negotiate from a stronger point than if they didn't have it all. It is essentially a bargaining chip.

Gates has urged North Korea to impose a moratorium on nuclear and missile testing to help revive six-party aid-for-disarmament talks involving the two Koreas, the United States, China, Japan and Russia.

The talks have been stalled for more than two years after the North declared the process dead in response to the U.N. Security Council's imposition of a new round of sanctions for its nuclear and missile tests in 2009.