South Korea and the US must be skeptical about future talks, not least because North Korea has no incentive to change. However, the North is vulnerable to financial pressure, as seen when the US once sanctioned an Asian bank that handled North Korean money.
New North Korea sanctions will target the banking sector in order to curtail the purchase and sale of weapons. The US-imposed sanctions also aim to stop the import of luxury goods for the elite surrounding leader Kim Jong-il.
Secretary of State Clinton announced new North Korea sanctions Wednesday, but many experts doubt the measures will persuade North Korea to resume talks over its nuclear program.
South Korea's President Lee Myung-bak may specifically blame North Korea's President Kim Jong-il for the Cheonan warship sinking on March 26. On Monday, President Lee plans to give a speech outlining his nation's response to the North Korea torpedo attack.
An Iranian company is the first to be penalized as the US uses stricter financial sanctions to curb Pyongyang's weapons program.