(CNN) The United States and North Korea are set for a "head-on collision" with neither side willing to give way, China's top diplomat has warned.

In a week of heightened tensions in the region, Foreign Minister Wang Yi cautioned the US in unusually frank language against the deployment of a controversial missile defense system in South Korea. The system is vehemently opposed by China.

But he also had strong words for North Korea, saying Pyonyang should suspend its nuclear weapons program.

"The two sides are like two accelerating trains coming towards each other," Wang told reporters in Beijing. "The question is, are the two sides really ready for a head-on collision?"

China's stern warning came in the week that North Korea launched four ballistic missiles and the US deployed the first components of the Terminal High Altitude Area Defense missile system (THAAD) in South Korea.

A report in China's state news agency Xinhua said the deployment of THAAD could kick off an "arms race" in the region. "More missile shields of one side inevitably bring more nuclear missiles of the opposing side that can break through the missile shield," the article said, suggesting China could accelerate its nuclear program.

Wang called on the US and South Korea to ease tensions in the region by suspending annual joint military exercises that antagonize North Korea, in exchange for Pyongyang halting its nuclear program.

"Nuclear weapons will not bring security," Wang said. "The use of force is no solution. Talks deserve another chance and peace is still within our grasp."

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He suggested China's role was to act as an early warning signal to avoid a potentially catastrophic collision on the Korea peninsula.

"(China's) priority now is to flash the red light and to apply brakes on both trains," he said.

China anxious over THAAD

Wang's press conference came a day after the US military revealed the controversial missile defense system had arrived in South Korea.

Pictures released by the United States showed the first pieces of the ballistic missile defense technology being unloaded at Osan Air Base in South Korea Monday night.

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The missile defense system is intended to counter North Korean aggression , according to the US military, but China is strongly opposing its deployment.

Beijing believes the missile system could be used to spy on their activities, rather than monitoring incoming North Korean missiles, Mark Tokola of the Korean Economic Institute of America said.

On Wednesday, Wang said South Korea must "cease and desist" the deployment, which he described as undermining Chinese security.

China's language 'unusual'

Professor Steve Tsang, director of London's SOAS China Institute, said Wang's language during the briefing was "unusual."

"They don't usually use this kind of language but it's not completely surprising given that they are not really effectively able to constrain or restrain what the North Koreans do and they're deeply unhappy about the US deployment of THAAD to South Korea," he said.

Tsang said China was very concerned about how the situation on the Korean Peninsula was developing. "If the Americans were seriously thinking about some sort of preemptive strike to take out North Korea's nuclear capabilities, it would be extremely messy ... China would have a huge price to pay," he said.

Euan Graham, director of the International Security Program at Sydney's Lowy Institute, said he was "very skeptical" of Wang's hopes for brokering a potential deal between North Korea and the US.

"To me, it speaks of a more tactical (statement) -- China's lost the initiative in the Korean Peninsula somewhat, not so much due to a proactive US policy to the region ... but in the way that North Korea has been throwing its weight around," he said.

Tillerson to visit China

US Secretary of State Rex Tillerson is heading to the region for talks next week, which are likely to include how to defuse the situation in North Korea.

Tillerson will touch down in Tokyo, Japan, on March 15 to begin his first east Asian tour since being sworn in . He'll then go to Seoul before making his final stop in Beijing on March 18.

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He'll be the second senior member of the Trump administration to tour East Asia since the new US president was inaugurated less than two months ago.

Secretary of Defense James Mattis already visited Japan and South Korea in early February , to reiterate US support for their two regional allies.

Wang said he had met Tillerson before, describing him as "a good listener and a good communicator."

"I hope and believe we can establish a good working relationship," he said.

Graham said the Trump administration's focus has been on East Asia compared to the previous Obama administration's broader engagement with southeast Asian countries.

"There was a genuine and concerted attempt to engage in bilateral relations (with) Singapore, the Philippines and Indonesia ... we don't see that same level of enthusiasm or engagement from this administration," he said.