KUWAIT, Sept 17 (Reuters) - Kuwait has ordered North Korea's ambassador to leave within a month as the Gulf country downgraded diplomatic relations with Pyongyang, a North Korean diplomat in the Gulf region said on Sunday.

The U.N. Security Council imposed new sanctions on North Korea earlier this month, and the United States called on countries to sever diplomatic and financial ties with it.

The diplomat, who asked not to be named, told Reuters the move followed Kuwait's decision to downgrade the North Korean diplomatic representation to charge d'affaires level.

In August, Kuwaiti authorities started taking measures against North Korea, such as cutting direct flights, after the Security Council imposed earlier sanctions on Pyongyang following missile tests.

Kuwait's announcement comes after U.S. President Trump met with the Gulf state's ruler in Washington earlier this month.

(Reporting by Ahmed Hagagy, writing by Aziz El Yaakoubi, editing by Louise Heavens)