BEIJING, Aug 7 (Reuters) - Chinese state media on Monday stressed the limits of new United Nations sanctions on North Korea, and also slammed the United States for its "arrogance", saying Washington needed to understand it also has a role in lessening tensions.

The United Nations Security Council unanimously imposed new sanctions on North Korea on Saturday that could slash its $3 billion annual export revenue by a third.

The U.S.-drafted resolution bans North Korean exports of coal, iron, iron ore, lead, lead ore and seafood following Pyongyang's two intercontinental ballistic missile tests in July. It also prohibits countries from increasing the current numbers of North Korean labourers working abroad, bans new joint ventures with North Korea and any new investment in current joint ventures.

In a front page commentary, the overseas edition of the ruling Communist Party's official People's Daily said North Korea's open flouting of U.N. rules with its missile launches meant that it had to be punished, but sanctions had to be targetted.

"Sanctions to the greatest possible extent must avoid causing negative impacts to ordinary people and to third countries, and avoid bringing disaster to the country in question's normal and legal trade and business exchanges with the outside world, people's normal lives and the humanitarian situation," it wrote.

"A precision blow is the essential part of sanctions."

China has repeatedly said that while sanctions need to be imposed, they cannot bring a final resolution to the North Korea issue, which has to be addressed by talks.

China has also called for Washington and Seoul to help lower tensions by reining in their military activities and drills on the peninsula, and by withdrawing the Terminal High Altitude Area Defense (THAAD) anti-missile system.

The influential Global Times, published by the People's Daily, said it an editorial that the United States needed to curb its "moral arrogance over North Korea".

"The West should be reminded to exercise restraint. If it believes it is only North Korea rather than the U.S. and South Korea as well to blame for the nuclear issue, this ill-fitting mindset will not help solve the crisis," the strongly nationalist publication said.

"The U.S. should aim for peace and co-existence rather than geopolitical dominance." (Reporting by Ben Blanchard; Editing by Lincoln Feast)