Seoul, South Korea (Reuters): South Korean President Moon Jae-in and his U.S. counterpart, Donald Trump, agreed to cooperate and apply maximum pressure and sanctions on North Korea in a telephone call on Monday, the South's presidential office said.

The U.N. Security Council unanimously imposed new sanctions on North Korea on Saturday aimed at pressuring Pyongyang to end its nuclear program. The sanctions could slash North Korea's $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 laborers working abroad, bans new joint ventures with North Korea and any new investment in current joint ventures.

During the hour-long phone call, Moon and Trump said they would continue cooperating to rein in North Korea, particularly ahead of a regular joint military drill set for late August, South Korean presidential office spokesman Park Su-hyun told a media briefing.

Moon was also cited as saying there was a need to show North Korea the door to dialogue is still open, should Pyongyang give up its nuclear program.

In a separate statement, the White House said the two leaders "affirmed that North Korea poses a grave and growing direct threat to the United States, South Korea, and Japan, as well as to most countries around the world".

"The leaders committed to fully implement all relevant resolutions and to urge the international community to do so as well," the White House said.

In a Twitter post, Trump said he was "very happy and impressed with 15-0 United Nations vote" on the sanctions.

North Korea has accused the United States and South Korea of escalating tensions by conducting military drills. North and South Korea are technically still at war because their 1950-53 conflict ended in a truce, not a peace treaty.