SEOUL (REUTERS) - North Korea's first and only law firm will suspend operations, the firm's principal said in a statement on Monday (Aug 1), as the country grows increasingly isolated.

Hay, Kalb & Associates is a joint venture between the North Korean state and British-French citizen Michael Hay, who has represented foreign clients in the capital Pyongyang for 12 years.

Mr Hay said he had made the decision based on "business and geopolitical principles".

"This decision has been taken only after lengthy and thorough deliberation and an examination of the continuing deterioration of inter-regional relations pertaining to the Korean peninsula," he said in a statement.

"It is not unreasonable to assume that no meaningful change or indicator of change in relations shall occur, if at all, until well after the United States Presidential Inauguration, on Jan 20, 2017," the statement said.

North Korea has come under growing diplomatic pressure since its January nuclear test and a long-range rocket launch in February, which led to a new UN Security Council resolution in March that tightened sanctions against Pyongyang.

The majority of Mr Hay's clients are foreign investors, many of whom have been negatively affected by the sanctions, he told Reuters.

"Sanctions are hurting legitimate foreign investors. There still is no credible, consistent evidence I see of DPRK companies hurting," Mr Hay said. DPRK stands for Democratic People's Republic of Korea, the North's official title.

Very few foreigners live or work in North Korea. Those who do are usually members of the diplomatic or non-government organisation community, although a small group of foreign investors have maintained a quiet and steady presence inside the country.

The suspension takes effect from midnight on Monday, Mr Hay said, with an official suspension scheduled for Aug 14, the firm's 12-year anniversary.

Mr Hay, who bills his firm as the only one in North Korea, said he will still maintain an office in Pyongyang.

North Korea has more than 8,000 law graduates, according to an official 2008 census, half of whom are based in Pyongyang. Most are employed by the state.