PYONGYANG, North Korea: North Korea on Monday was expelling a BBC journalist it had detained days earlier for allegedly "insulting the dignity" of the authoritarian country, while it continued to keep other foreign media away from the first-in-decades ruling party congress they had been invited to attend.

Rupert Wingfield-Hayes was not among the scores of foreign media covering the Workers' Party congress; he had covered an earlier trip of Nobel laureates and had been scheduled to leave Friday. Instead, he was stopped at the airport, detained and questioned.

O Ryong Il, secretary-general of the North's National Peace Committee, said the journalist's news coverage distorted facts and "spoke ill of the system and the leadership of the country." He said Wingfield-Hayes wrote an apology, was being expelled Monday and would never be admitted into the country again.

The BBC says Wingfield-Hayes was detained Friday along with producer Maria Byrne and cameraman Matthew Goddard, and that all were taken to the Pyongyang airport.

More than 100 foreign journalists are in the capital for North Korea's first party congress in 36 years, though they have been prevented from actually covering the proceedings and the more than 3,400 delegates. They've had to depend on reports from state media, which reports event hours later or even the next day. Officials have kept the foreign media busy with trips around Pyongyang to show them places it wants them to see.

The Korean Central News Agency said Monday that the congress was to enter its fourth day. On Sunday, the congress adopted a resolution to strive toward a more prosperous and modern economy and stressed that it will push for the peaceful reunification of Korean Peninsula, but warned that if Seoul "opts for a war" its military will mercilessly wipe out all opposition.

Also Sunday, leader Kim Jong Un delivered a three-hour speech to delegates to review the country's situation and progress since the last congress was held in 1980, before Kim was born.

In his speech, Kim announced a five-year economic plan, the first one made public since the 1980s, when his grandfather, "eternal president" and national founder Kim Il Sung, was in power.

The speech, in which he said North Korea was a responsible nuclear state that will not use its nuclear weapons first unless its sovereignty was threatened, underscores Kim's dual focus on building up the military while trying to kick-start the North's economy, which has seen some growth in recent years but remains hamstrung by international sanctions over its nuclear program.

Walking a fine balance between the two, he said the North is willing to develop friendly relations even with countries that had in the past been hostile toward it — a possible overture to the United States.

But he made clear that the North has no intention of unilaterally giving up its nuclear program or bending to international pressure aimed at forcing its regime into decline or collapse.

Kim said North Korea "will sincerely fulfill its duties for the nonproliferation of nuclear weapons and work to realize the denuclearization of the world," but that statement is predicated on other countries — again, mainly the United States — also giving up their weapons, a highly unlikely scenario.

On South Korea, Kim Jong Un stressed the need for talks to ease cross-border animosities and emphasized reunification under a federal system, a decades-old proposal that would largely keep the North's brand of socialism intact that has received no traction with Seoul.

"But if the South Korean authorities opt for a war, persisting in the unreasonable 'unification of social systems,' we will turn out in the just war to mercilessly wipe out the anti-reunification forces and achieve the historic cause of national reunification, long-cherished desire of all Koreans," he said.

South Korea's Unification Ministry on Monday dismissed Kim's offer for talks as "propaganda" that lacks sincerity. Spokesman Jeong Joon Hee told reporters that talks can resume only when North Korea demonstrates how sincere it's about nuclear disarmament.

Though North Korea appears to be making significant progress in developing what it calls a nuclear deterrent, its economy is still recovering from the collapse of the Soviet Union and its East bloc allies and a massive famine in the 1990s. It depends heavily on trade with China and has fallen light years behind its southern rival.

Kim identified a number of key areas, including the country's power supply, agriculture and light-manufacturing production, as critical parts of the program. Kim stressed that the country needs to increase its international trade and engagement in the global economy, but didn't announce any significant reforms or plans to adopt capitalist-style marketization.

Still remaining on the agenda of the congress, which gathers more than 3,400 delegates at the ornate April 25 House of Culture, are elections to give Kim the party's top post — he is already its first secretary, and his father posthumously holds the title of "eternal general-secretary" — and for other party leadership positions.

Though no date has been announced, and surprises can never be ruled out, the congress was expected to go on for a couple more days.

Mass rallies will likely be held to mark its conclusion in a celebratory fashion.