A last-minute attempt to restart stalled talks between North and South Korea collapsed in recriminations today as each government's negotiators assailed the other's as intransigent and then headed home.

Meanwhile, in another sign of the increasing tension on the strategic peninsula, a former U.N. diplomat said in Beijing that North Korean officials had informed him of plans to test a ballistic missile.

Yasushi Akashi, a former U.N. undersecretary general, said at a news conference that a section chief in the North Korean Foreign Ministry had informed him of the missile test plans during Akashi's visit last week to the isolated hermit nation.

U.S. officials have been warning of a launch for the past week, charging that it could derail efforts to improve ties with the hard-line Communist government. The test of a three-stage North Korean missile Aug. 31 sent a shock wave through northeastern Asia when it flew through Japanese airspace and splashed down in the Pacific Ocean.

The announcements in Beijing mark a somber ending to the past two weeks, which began with hope of at least a small step toward easing tensions on the Korean peninsula. South Korea and North Korea resumed talks on June 22 after bickering for 14 months over the venue and the agenda. South Korea was pushing to reunite the 10 million Koreans separated since the Korean War ended in 1953. North Korea, which has been suffering a famine because of disastrous economic policies and bad weather, wanted more aid.

Since the talks began, however, tensions have increased because of North Korean naval incursions into South Korean waters and detentions of a South Korean and an American citizen. The South Korean has been released; the American still has not received a consular visit after two weeks in custody.

The sides met four times, including a final 90-minute session this morning, with the talks going nowhere. At one point, North Korea held up the negotiations until a South Korean cargo ship containing fertilizer landed in North Korea. At another point, the confrontation at sea, during which South Korean warships sank a North Korean torpedo vessel, sullied the negotiating atmosphere.

In today's talks, South Korean Vice Unification Minister Yang Young Shik and North Korea's lead negotiator Pak Yong Su reiterated previous positions, said South Korean Embassy spokesman Wi Keyei Chul.

Yang blasted Pyongyang for not negotiating in good faith and for violating an agreement last month to discuss family reunions in exchange for Seoul's shipment of 200,000 tons of fertilizer.

"We greatly regret that North Korea has not implemented the . . . agreement," Yang said. "We expect the northern side to respond to the dialogue as agreed."

Pak countered that South Korea did not meet its fertilizer obligations.

"They violated the agreement and stuck to only one problem," Pak said. At one point in the meeting, Pak threatened to turn South Korea into a "sea of fire."

It is unclear what role, if any, China played in the recent hardening of North Korea's position or in its reported plans to test a new missile. Earlier this year, Chinese officials told officials close to South Korean President Kim Dae Jung, currently in the United States, that they would try to persuade Pyongyang not to test a new missile.

Lately, however, Western diplomats have expressed unease with China's position, especially after NATO bombed the Chinese Embassy in Belgrade on May 7. After the bombing, China said it was suspending cooperation with the United States on arms control and international security matters.

CAPTION: South Korea's Yang Young Shik says talks with the North have ended.