US President Barack Obama signed legislation which imposes a new set of broader and more stringent bans against North Korea on Thursday.

The White House said the measures tighten sanctions against anyone who imports goods related to weapons of mass destruction into North Korea, or anyone who knowingly engaged in human rights abuses.

The expanded sanctions seek to deny North Korea the money it requires in order to develop miniature nuclear warheads and the long-range missiles which would carry those warheads.

The legislation also authorizes the US to fund some $50 million (45 million euro) for radio broadcasts into North Korea to support humanitarian assistance programs. The money is to be spread out over five years.

Lawmakers in Congress overwhelmingly and quickly approved the bill earlier this month.

North Korea went forward with its fourth nuclear test, followed by a long-range rocket launch on February 7, despite a UN resolution prohibiting such action.

Analysts consider these steps as clear signs that North Korean leader Kim Jong Un is determined to create a missile capable of striking the US mainland.

The new US measures against North Korea come amidst delicate negotiations between Washington and China over a UN Security Council resolution for additional sanctions. China has said it is concerned that the measures could devastate North Korea's economy.

rs/kms (AP, AFP, Reuters)