United Nations, Jun 3 (IANS): The UN Security Council has expanded sanctions against North Korea in response to a series of missile tests conducted by Pyongyang this year.

The measures imposed a travel ban and asset freeze on four entities and 14 officials, including the head of North Korea's overseas spying operations.

The Council voted unanimously on Friday to back the sanctions after weeks of negotiations between the US and China, CNN reported.

The new asset and travel freeze targeted senior officials and its core military apparatus that were directly responsible for the regime's illicit nuclear and ballistic missile programmes, South Korea Ambassador to the UN, Cho Tae-Yul, told the council.

The list of expanded sanctions also included state officials and banks.

North Korea's strategic rocket force, the Koryo Bank and two trading firms were also added to the list.

The Koryo Bank was linked to a party office that managed the finances of North Korea's top officials, including leader Kim Jong-un.

Though US military exercises in the Korean peninsula had been controversial in the international community, US Ambassador to the UN Nikki Haley urged Security Council members to enforce the new sanctions.

"The Security Council is sending a clear message to North Korea today -- stop firing ballistic missiles or face the consequences," Haley said after the vote.

"Countries must also do more to break up North Korean smuggling rings, and cut off the sources of funding North Korea uses to pay for the development of weapons of mass destruction and the means to deliver them," she said in a statement.

Ambassadors of countries such as France and Italy supported the resolution but stressed that sanctions are only a means to an end, not a goal realised.