The United States today offered North Korea an online welcome to Twitter but warned the reclusive regime it might wind up with more than it bargained for entering the connected world.

The US State Department's chief spokesman, Philip Crowley, turned to his own account on the popular micro-blogging site to "welcome North Korea to Twitter and the networked world."

But Crowley told North Korea -- whose tweets have so far consisted of links to its famously strident anti-US and anti-Seoul statements -- that "we use Twitter to connect, to inform and to debate."

"The North Korean government has joined Twitter, but is it prepared to allow its citizens to be connected as well’" Crowley said in another tweet.

"The Hermit Kingdom will not change overnight, but technology once introduced can't be shut down. Just ask Iran," he wrote.

It was a pointed reference to last year's major street protests to Iran, where opponents of the hardline theocratic regime organised and distributed footage of banned demonstrations through Twitter and other new technology.

North Korea, one of the world's most controlled states, is believed to have an elite unit of hackers but few of its citizens have access to a computer, let alone the Internet.

But, even if it is only for curiosity value, Pyongyang's Twitter account -- which is only in Korean -- has rapidly attracted followers.

As of early afternoon today in Washington, North Korea's account, @uriminzok, had some 4,600 followers -- about 1,000 more than Crowley had at @pjcrowley.