A group of South Korean businessmen on Wednesday failed to deliver a protest letter to North Korea over its unilateral decision to raise wages for workers at the Kaesong Industrial Complex, a government official said.

The 14 members of the council of South Korean companies operating in the zone visited there and had a two-hour meeting with the North's related officials.

They included Pak Chol-su, deputy head of the Central Special Development Guidance Bureau in charge of running the complex, according to the South's official, who spoke on the condition of anonymity.

The letter included the council's opinion that it would help increase investors' trust in the Kaesong complex for the two Koreas to set the wage level through mutual consultations, he added.

But the North refused to receive the letter.

Concerns have grown over the fate of the joint venture, which is the last-remaining major inter-Korean project.

In February, the North announced plans to raise the minimum wage for its workers from $70.35 to $74 starting in March.

A total of 124 South Korean firms operating in the complex will begin to pay the March wage for around 53,000 North Korean employees on April 10.

The companies, mostly small and medium-sized ones, are sandwiched between the North's pressure and the South Korean government's stern response. The unification ministry warned of legal and administrative punishment against those following Pyongyang's measure.

Heading to the North's border town of Kaesong earlier in the day, Chung Ki-sup, who leads the council, said the South's government needs to address the North's strong protest against the cross-border spread of anti-Pyongyang leaflets by activists here.

It's one of the biggest obstacles to efforts to resume inter-Korean dialogue, he pointed out.

Park Sang-hak, a North Korean defector campaigning against Pyongyang, said he would organize an event to fly half-a-million leaflets toward the North by the use of helium balloons on March 26.

Also to be sent are thousands of DVDs and USBs containing the copies of "The Interview," a Hollywood comedy that involves a plot to kill the North's leader, Kim Jong-un, he said.

"The problem of the Kaesong Industrial Complex can be resolved easily if the upcoming leaflet scattering is curbed," Chung claimed.

The Park Geun-hye administration maintains that it has no legal ground to forcibly block the leaflet campaign, which is tied to the freedom of speech.

Unification ministry officials have instead advised activists to make a "wise" choice in consideration of worries that their leaflet campaign may jeopardize the safety and security of residents in border areas.

"It's not appropriate to link the leaflet-scattering issue with our response to North Korea's unilateral and unjust demand for a wage hike," ministry spokesman Lim Byeong-cheol said at a press briefing.

He urged the North to accept the South's offer of talks on the wage dispute and other pending issues.

As to the matter of a land use fee for the Kaesong facilities, Lim said the government will seek consultations with the North "at a proper time."

Launching the facilities in 2004, the North agreed to exempt the South from a land use fee for a decade.

"Our government is aware that the North is supposed to impose a land use fee from this year," he added. (Yonhap)