U.S. President Donald Trump has urged China to do more to rein in its neighbour, which has pursued its weapons programmes in defiance of United Nations sanctions and worldwide condemnation.
The official also refuted criticism that the administration has been inconsistent on the THAAD deployment.
North Korea announced that it had successfully detonated a hydrogen bomb on Sunday, its sixth and most powerful nuclear test so far.
Meanwhile, Russian President Vladimir Putin warned on Wednesday that the North Korean nuclear crisis can not be resolved by sanctions alone, and urged the global community not to push Pyongyang into a corner.
More than 30 people were hurt when about 8,000 police broke up a blockade near the site by about 300 villagers and members of civic groups opposed to the THAAD deployment, fire officials said.
The North's official news agency again recently slammed pending sanctions by the United Nations, and Nikki Haley, the USA ambassador to the UN, for accusing North Korea's leader Kim Jong-un of "begging for war".
"Given the new developments on the Korean peninsula, China agrees that the UN Security Council should respond further by taking necessary measures", Chinese foreign minister Wang Yi said.
The decision to deploy Thaad, created to shoot down short- to medium-range missiles mid-flight, has drawn strong objections from China.
Putin says solving North Korea crisis without diplomatic tools is 'impossible'
Two launchers and a powerful radar are already in place at the site as part of the US Terminal High Altitude Area Defence (THAAD) system.
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.
In a written statement released late Friday evening President Moon explained that adding more launchers to the contentious high-tech missile defense system was the best choice his government could make considering an unprecedented security threat from North Korea.
U.S. President Donald Trump has said that all options are on the table when it comes to dealing with the rogue state, and although he would prefer not to use military action, it would be a "sad day" for North Korea if he did.
Geng told reporters that China had complained to the US and South Korea and urged them to "take seriously the security concerns and interests of China and other regional countries".
Chinese foreign minister Wang Yi said Beijing supports further United Nations action against North Korea but also wants to see renewed efforts to begin dialogue involving all sides.
South Korea President Moon Jae-in held discussions on North Korea with Japanese Prime Minister Shinzo Abe on the sidelines of the Eastern Economic Forum in Vladivostok, hosted by Russian President Vladimir Putin. The US and South Korea should "immediately stop the deployment process and withdraw relevant equipment", Geng said.
It also said Macron had expressed France's "solidarity" with Japan.
During his election campaign earlier this year, President Moon was a noted skeptic of THAAD, and called for greater dialogue with North Korea.