North Korea on Wednesday accused South Korea's new president Park Geun-Hye of slander and provocation after she warned Pyongyang to abandon its nuclear weapons or face collapse.

The North's Committee for the Peaceful Reunification of Korea, a state body in charge of propaganda and inter-Korean affairs, said Park was following the hardline anti-North stance of her predecessor Lee Myung-Bak.

"If she keeps to the road of confrontation like traitor Lee, defying the warnings of the DPRK (North Korea), she will meet a miserable ruin," it said.

The committee urged Park to "behave with discretion, clearly mindful that a wrong word may entail horrible disaster" at a time of elevated military tensions on the Korean peninsula.

"The present chief executive of South Korea made invectives slandering the DPRK," it said, referring to her speech Tuesday marking the third anniversary of the sinking of a naval vessel by what Seoul insists was a North Korean submarine.

Park warned North Korea that its only "path to survival" lay in abandoning its nuclear and missile programmes, and urged Pyongyang to "change course".

The North's committee slammed Park's "confrontational rhetoric", saying it was "an unpardonable provocation... and a blatant challenge.

The committee also repeated a previous sexist swipe at Park, South Korea's first female president, painting her as overbearing and manipulative.

"We have already seriously warned against the venomous swish of skirt," it said.

"Swish of the skirt" (or "chima baram") is a common, derogatory Korean term used to criticise women seen as overly bossy or domineering.

North Korea's propaganda machine criticised Park repeatedly during the presidential campaign, warning that she would adopt the dictatorial methods of her father, the late military strongman Park Chung-Hee.

But it has been cautious in criticising Park since she was sworn in only a month ago as South Korea's first female president.

North Korea carried out a successful long-range rocket test in December and a third nuclear test last month.

Both events triggered UN sanctions that infuriated the North, which has spent the past month issuing increasingly dire threats about unleashing an "all-out war" backed by nuclear weapons.

N. Korea to hold meeting of top leaders: report
Seoul (AFP) March 27, 2013 - North Korea's top leaders are to meet in the coming days to decide on an unspecified "important" issue, official media said Wednesday, as tensions simmer on the Korean peninsula.

The Political Bureau of the Communist Party's Central Committee will convene its plenary meeting before the end of March to "discuss and decide an important issue for victoriously advancing the Korean revolution", the Korean Central News Agency said.

KCNA did not specify the date for the meeting, which will also reportedly make a "drastic turn" in accomplishing the North's Juche (self-reliance) revolutionary cause.

Analysts in Seoul said decisions on issues concerning security, international relations and reshuffle of personnel were likely to be made at the meeting and approved by the North's rubber-stamp parliament, meeting on April 1.

"They will discuss how to handle the nuclear issue, inter-Korean relations and North Korea's long-standing demand for a peace treaty with the United States," Professor Yang Moo-Jin of the University of North Korean Studies in Seoul told AFP.

Yang said Jang Song-Thaek, uncle of North Korea's leader Kim Jong-Un, could be appointed as prime minister with the task of resuscitating the country's struggling socialist economy.

There could also be changes in the make-up of the powerful Presidium of the Political Bureau.

Vice Marshall Hyon Yong-Chol, the chairman of the Joint Chiefs of Staff, could join the body, which would further strengthen the military's say over key state affairs, said Yang.

Angered by UN sanctions imposed after its nuclear test in February, Pyongyang has issued a wave of threats over the past month -- ranging from a surgical military strike to nuclear war.

North Korea's military put its "strategic" rocket units on a war footing Tuesday, with a fresh threat to strike targets on the US mainland, Hawaii and Guam, as well as South Korea.

The move came as South Korea marked the third anniversary of the sinking of its naval vessel "Cheonan" by what Seoul insists was a North Korean submarine.

In the latest sign of tensions, a South Korean soldier standing on guard at the inter-Korean border threw a grenade towards a moving object in the dark early Wednesday, sparking a short-lived alarm, the defence ministry said.

At daylight, a patrol searched the area but there was no trace of any infiltration from North Korea, a ministry spokesman said.

A precautionary alert, which had been issued for South Korean units in the northeastern county of Hwacheon, was consequently lifted.