A US-drafted resolution obtained by AFP also called for a ban on textile exports and an end to payments made to North Korean laborers sent abroad.
U.S. President Donald Trump said on Wednesday that military action against North Korea was not a first choice and said he had had a strong and frank discussion with China's President Xi Jinping about the issue.
"President Xi would like to do something. We'll see whether or not he can do it. But we will not be putting up with what's happening in North Korea," Trump told reporters at the White House.
"I believe that President Xi agrees with me 100 percent... We had a very, very frank and very strong phone call."
Trump's comments follow a statement from China's Foreign Ministry detailing the call, which says Xi told Trump China is focused on solving the Korean issue through talks and peaceful means.
China military drills
Meanwhile China's air force conducted military drills in seas adjacent to the Korean peninsula, an official report has said, as tensions soared over North Korea's pursuit of nuclear weaponry.
The defence battalion simulated warding off a "low-altitude, surprise" attack off China's east coast, and practised defending against "nuclear and biological weapons", according to China Military Online, the news website of the Chinese army.
The purpose of the drill in the Bohai Gulf early Tuesday was not immediately clear.
It came after Pyongyang on Sunday triggered global alarm with its most powerful nuclear blast to date, claiming to have successfully tested a hydrogen bomb.
Song Zhongping, an independent defence and foreign affairs analyst, said the drill was likely unrelated to the situation on the Korean peninsula.
South Korea has detected signs that the North is preparing another missile launch. Pictured is Kim Jong-un (centre) Source: AAP
"The Chinese navy is currently focused on improving its defence capabilities, therefore paying more attention to developing anti-missile capability," Song told AFP.
China has for some time been engaged in a modernisation of its once-backward armed forces, seeking military clout commensurate with its economic might, a drive that has caused unease among its regional neighbours.
Foreign ministry spokesman Geng Shuang said at a regular news briefing in Beijing on Wednesday that he had no information on the drill.
Analysts say North Korea's escalating nuclear provocations are putting putative ally China in an increasing bind and may be part of a strategy to twist Beijing's arm into orchestrating direct talks between Pyongyang and Washington.
China has consistently railed against recurring US-South Korean war games that are directed at deterring a North Korean attack, but which China blames for fanning regional tensions.
South Korea had responded to the North's nuclear test by saying it was strengthening its defences, in part by deploying more US-made Terminal High-Altitude Area Defense (THAAD) missile launchers.
The deployment has infuriated China, which has long argued it will destabilise the region and has retaliated against Seoul through unofficial economic sanctions.
The South also carried out an early-morning volley of ballistic missiles Monday simulating an attack on the North's nuclear test site, followed Tuesday by naval drills.
