Global credit rating agency Standard & Poor's has warned of a possible downgrading of South Korea’s sovereign credit rating amid escalating geopolitical tensions following North Korea’s sixth nuclear test.

S&P sovereign analyst Kim Eng Tan told Bloomberg news agency on Monday that there are increasing downward pressures on Asia’s fourth largest economy, however, they are not considering downgrading South Korea's credit rating for now.

S&P raised the country’s rating by a notch from AA- to AA in August of last year, and has maintained the rating and its “stable” outlook ever since, despite Pyongyang-triggered tensions in the region.