South Korea decided to impose new sanctions against 40 individuals and 30 entities for Pyongyang’s nuclear weapon programme and ban any ships that had stopped at North Korean ports in the last six months.
Seuol said on Tuesday that the new measures are aimed to prevent shipping firms and trading companies from doing business with the North to isolate it even more.
North Korea’s fourth nuclear test in January and a long-rocket launch last month triggered South to impose more one-sided sanctions following a UN Security Council resolution.
South Korean Foreign Minister Yun Byung-se told reporters that they would also stop taking part in a pilot project signed in 2013 between South Korean President Park Geun-hye and Russian leader Vladimir Putin to brought Russian coal to South Korea through North Korean port, Rajin.
The government said a Singaporean and a Taiwanese nationals who are the heads of a shipping firm and a trading company are among the sanctioned people and they are subjected to financial restrictions.
Leon Panetta, a former CIA director and US defense secretary, on Monday said illegal trade along with the border between North Korea and China is one of the loopholes in international efforts to deter Pyongyang’s missile development.
Byung-se suggested in late February to set vote on new sanctions on North Korea at the UN-backed conference after North Korea's nuclear test and satellite launch on February 6.
North Korea has been under UN sanctions since 2006.
In May 2015, US, Japanese and South Korean envoys met in Seoul and agreed on stepping up pressure over North Korea’s long-disputed nuclear programme which has been perceived as a major threat by the respective countries.
The tension in the region is still high as US and South Korea began joint military exercises on March 6.
South blames North for hacking phones
South Korea’s spy agency said on Tuesday that smartphones belonging to a number of key government officials were hacked as part of a series of cyber-attacks by North Korea.
The National Intelligence Service (NIS) said that the North stole phone numbers and texts from the smartphones of dozens of key South Korean officials between late February and early March.
The hackers sent text messages to the South Korean officials, trying to lure them to links infected with badware that could capture the phone numbers to other officials.
The attack also aimed at a server of a major software firm providing security software for internet banking.
North Korean hackers sent baiting emails to employees of two provincial railway operators in order to steal their account details and passwords. The attack aimed at controlling the railway traffic systems.
Last year alone, North Korea contaminated some 60,000 personal computers in the South and abroad, turning them into "zombie" PCs that can be used as weapons for cyber attacks, the agency said.