North Korea sounded a bellicose note in its first communication with the outside world since the death of leader Kim Jong-il, saying its confrontational stance against South Korea would not change and labelling its opponents foolish.

Since Kim Jong-il died on December 17, the outside world has been watching to see whether his son Kim Jong-un, aged in his 20s, would stick to its hardline military first policies that have seen the isolated nation move closer to nuclear weapons capacity.

On this occasion, we solemnly declare with confidence that foolish politicians around the world, including the puppet forces in South Korea, should not expect any changes from us, a broadcaster on state television said on Friday.

She was reading a statement from the National Defence Commission, the top body in the militarised and impoverished state under Kim Jong-il.

In a break from the black mourning clothing worn since Kim Jong-il's death, the broadcaster wore dark red clothes and almost shouted her defiant message.

North Korea has a long history of using bellicose phrases against the South, especially since the conservative government of Lee Myung-bak took office in 2008 and ended a policy of engagement with the North.

It has threatened to turn the South's capital Seoul into a sea of fire on numerous occasions and repeated that rhetoric again on Friday.

We will never engage with the Lee Myung-bak administration, said the announcer.

The sea of bloody tears from our military and people will follow the puppet regime until the end. The tears will turn into a sea of revengeful fire that burns everything.

In 2010, the North launched an artillery barrage that killed South Korean civilians for the first time since the end of the Korean War in 1953. It was blamed for sinking a South Korean warship earlier that year, although it denies it did.

Little is known of Kim Jong-un, who had been groomed for government since 2009.

He has been dubbed Supreme Commander in North Korea and is expected to rule with the aid of key figures like his uncle Jang Song-thaek, at least in the early stages of the power transition.

Expecting any change from the North on our part would be foolish, said Chung Young-tae, an analyst at the Korea Institute of National Unification in Seoul, a government think-tank.

South Korea's government did not formally respond to the comments from the North.

NUCLEAR CAPACITY

Under Kim Jong-il, who died earlier this month aged 69, North Korea conducted two nuclear tests and a top observer of its nuclear programme said this week the country may only be a few years away from developing a nuclear tipped missile.

Few however expect the North to launch a full scale attack on South Korea. Pyongyang's main backer, China, has repeatedly urged a peaceful solution on the Korean peninsula.

Despite the freeze in official relations between North and South, the two sides held talks this year which North Korea leaked, embarrassing the government in Seoul.

North Korea needs food aid from the government in Seoul as up to a third of its population is malnourished, according to the United Nations.

These forms of messages have led to conversation before, said Chung.

(Reporting by Seoul bureau; Editing by Raju Gopalakrishnan)