N. Korea party meet ends adding just more power to Kim's limitless powers

Pyongyang vows to expand the country's nuclear and missile arsenal in violation of the UN sanctions.

North Korea's rare Workers' Party congress concluded by anointing ruler Kim Jong-un the chairman of the party and vowing to expand the country's nuclear and missile arsenal in violation of the UN sanctions.

North Korea experts said the feted party congress concluded after achieving its sole goal of entrancing Kim's grip on power in the isolated country.

"Kim's new position makes it very clear that the whole party meeting is only aimed at solidifying his legitimacy as the new leader," a prominent North Korean defector said, according to the AFP.

"All past leaders of the party were named at a party congress ... so this was a perfect coronation," Koh Young-hwan, a former North Korean diplomat who now heads the state-run Institute for National Security Strategy in Seoul added.

Around 130 foreign journalists were allowed a brief entry to convention hall on Monday, after being kept away from the proceedings for two days.

Earlier on Monday Pyongyang had expelled BBC journalist Rupert Wingfield-Hayes after questioning him for eight hours.

Authorities said they will never "allow him back into the country for any reporting" after accusing him of "speaking very ill of the system and the leadership".

Chinese President Xi Jinping congratulated Kim on the promotion but did not mention the North's nuclear programme over which China shares the western concerns.

"We will make efforts together with the DPRK side to bring happiness to the two countries and their peoples and contribute to peace, stability and development in this region by steadily developing the Sino-DPRK friendship and cooperation," Xi said, state news agency KCNA reported.

"I wish the Korean people fresh success in carrying out the cause of socialism under the leadership of the WPK (Workers' Party of Korea) headed by Chairman Kim Jong Un," Xi said.

Aside from the coronation of Kim the party congress focused on the reunification theme saying Pyongyang will retaliate against any attack on it by the "anti-reunification forces'.

"... if the South Korean authorities opt for a war ... we will turn out in the just war to mercilessly wipe out the anti-reunification forces," reserving familiar venom for Seoul.