Thousands of policemen violently dispersed peace activists and residents living near the site of the THAAD missile defense system. Picture: Xinhua/Yao Qilin

Seoul - Protesters clashed with thousands of police at a South Korean village on Thursday as components of a controversial system to guard against North Korean missiles were deployed, while China and the United States discussed options to deal with Pyongyang.

The United States wants the United Nations Security Council to impose an oil embargo on North Korea, ban its exports of textiles and the hiring of North Korean labourers abroad, and subject leader Kim Jong Un to an asset freeze and travel ban, according to a draft resolution seen by Reuters on Wednesday.

Pressure from Washington has racheted up since North Korea conducted its sixth and largest nuclear test on Sunday. That test, along with a series of missile launches, showed Pyongyang was close to achieving its goal of developing a powerful nuclear weapon that could reach the United States.

Amid the rising tensions, Seoul installed the four remaining launchers of the U.S. anti-missile Terminal High Altitude Area Defense (THAAD) system on a former golf course in the south early on Thursday. Two launchers had already been deployed.

More than 30 people were injured when around 8 000 South Korean police broke up a blockade of about 300 villagers and civic groups opposed to the THAAD system deployment, fire officials said.

The decision to deploy the THAAD system has drawn strong objections from China, which believes its radar could be used to look deeply into its territory and will upset the regional security balance.

U.S. President Donald Trump has urged China, North Korea's biggest ally and trading partner, to do more to rein in its neighbour.

U.S. Treasury Secretary Steve Mnuchin said he has an executive order ready for Trump to sign that would impose sanctions on any country that trades with Pyongyang if the United Nations does not put additional sanctions on North Korea over its nuclear tests.

Trump and Chinese President Xi Jinping committed on a phone call on Wednesday to "take further action with the goal of achieving the denuclearisation of the Korean peninsula", the White House said.

"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, although he offered no specifics.

"I believe that President Xi agrees with me 100 percent," he said.

Asked whether he was considering a military response to North Korea, Trump said: "Certainly, that's not our first choice, but we will see what happens."

Xi told the U.S. president during their 45-minute call that the North Korean issue must be resolved through "dialogue and consultation".

The United States had set aside for now consideration of terminating a U.S. trade agreement with South Korea, a senior administration official said on Wednesday. 

The trade issue is unrelated to North Korea but has been a source of tension between the two allies.

Japanese Prime Minister Shinzo Abe and South Korean President Moon Jae-in spoke at a regional meeting in the eastern Russian city of Vladivostok and agreed to persuade China and Russia to cut off oil to North Korea as much as possible, according to South Korean officials.

Abe also invited Moon to a trilateral meeting between China, Japan and South Korea in Tokyo and Moon said he would be happy to attend if such a summit happened.

Japan's Kyodo news agency reported that Abe and Moon would seek Russian and Chinese support for new sanctions against the North.

However, sanctions have so far done little to stop North Korea boosting its nuclear and missile capacity as it faces off with Trump.

China and Russia have advocated a "freeze for freeze" plan, where the United States and South Korea would stop major military exercises in exchange for North Korea halting its weapons programmes, but neither side is willing to budge.

North Korea says it needs to develop its weapons to defend itself against what it sees as U.S. aggression.

South Korea and the United States are technically still at war with North Korea after the 1950-53 Korean conflict ended with a truce, not a peace treaty.