South Korea has sanctioned the head of North Korea's intelligence agency over illicit cyber activities following Pyongyang's recent launch of an intercontinental ballistic missile, Seoul's foreign ministry said Wednesday.

Pyongyang is already under international sanctions for its atomic bomb and ballistic missile programs, which have seen rapid progress under North Korean leader Kim Jong Un.

The announcement came weeks after Seoul, Tokyo, and Washington launched new three-way initiatives encompassing measures to address North Korea's cybercrime, cryptocurrency, and money laundering activities, which are believed to fund the country's nuclear and missile programs.

Ri Chang Ho, the head of Pyongyang's Reconnaissance General Bureau, has been sanctioned for his involvement in "earning foreign currency through illegal cyber activities and technology theft", Seoul's foreign ministry said in a statement.

His activities have contributed to "generating revenue for the North Korean regime and procuring funds for its nuclear and missile activities", it added.

Ri heads the agency that is believed to be the parent organization for North Korean hacking groups Kimsuky, Lazarus, and Andariel, which have been previously sanctioned by Seoul.

Along with Ri, Seoul has sanctioned seven other North Korean individuals, including former China-based diplomat Yun Chol, for being involved in the "trade of lithium-6, a nuclear-related mineral and UN-sanctioned material for North Korea".

The blacklisted individuals are barred from conducting foreign exchange and financial transactions with South Korean nationals without prior authorization from Seoul, measures that analysts say are primarily symbolic given the extremely limited trade between the two countries.

Seoul has now blacklisted 83 individuals and 53 entities related to Pyongyang's weapons programs since October last year, its foreign ministry said. 

North Korea has recently ramped up its nuclear and military threats, successfully launching a reconnaissance satellite in November and testing its most advanced ICBM this month.

Kim said last week that Pyongyang would not hesitate to launch a nuclear attack if "provoked" with nukes.

"Our government has made it clear that North Korea's provocations will inevitably come with a price," Seoul's foreign ministry said in its statement Wednesday.

"Our government will continue to closely cooperate with the international community… to make North Korea realize this fact, cease provocations, and engage in dialogue for denuclearisation."

According to Seoul, Tokyo, and Washington, Pyongyang stole as much as $1.7 billion in cryptocurrency last year alone and supported its weapons programs in part by gathering information through "malicious cyber activities".

In June, Seoul sanctioned a Russian national over allegedly founding a North Korean front company in Mongolia to assist Pyongyang in evading sanctions to secure financing for its banned weapons programs.