A North Korean spokesman said the US should halt sanctions and military exercises with South Korea if it wants a nuclear-free peninsula."If the US is really interested in the denuclearization of the Korean peninsula, it should halt the military exercises and sanctions that destroy the mood for dialogue," North Korean spokesman Ri Tong Il told reporters in Hanoi on Thursday.RELATED:Gates: North Korea must face account in ship sinkingChina avoids blaming North KoreaUS Secretary of State Hillary Clinton announced Wednesday the US would impose new sanctions on the reclusive North four months after the sinking of a South Korean warship, the Cheonan, that killed 46 sailors and has been blamed on Pyongyang. The North has denied involvement.The allies announced they would hold four days of joint military exercises starting Sunday. The United States and South Korea announced they planned to hold joint military exercises in response to the Cheonan's sinking.The United States already has applied trade and other sanctions to North Korea. Additional punishment could include the US putting North Korea back on its list of state sponsors of terrorism, although legal opinions differ on whether the Cheonan attack was terrorism.