Such frictions could complicate efforts to get a united push for the regime in North Korea to abandon its nuclear weapons and missiles.
In a separate meeting with South Korean President Moon Jae-in, Xi said the situation on the Korean peninsula had reached a "pivotal" stage, Yonhap news agency reported.
Moon agreed to make his first visit to China next month, said presidential chief press secretary Yoon Young-chan in a press briefing, which would mark his first visit to the country since he took office.
Pyongyang remains silent despite repeated invitations from the South Korean president to take part in the Olympic Games to be held February 9-25.
Moon, however, insisted now was still time to focus on keeping maximum pressure and sanctions against the impoverished North.
According to this explanation, the only reason Xi brought up the THAAD issue again was to put weight on bringing the issue to a close and normalizing South Korea-China relations. Earlier in the year, Seoul deployed a USA missile defence system, which Beijing regards as a threat to its security, but which Seoul feels is necessary in light of the provocation by Pyongyang.
The Korean government also assuaged Beijing's security concerns with the so-called "three nos", meaning no additional Thaad deployments, no joining of a broader U.S. missile defense (MD) system and no Korea-U.S. -Japan military alliance. "We hope the trilateral summit will resume soon", he said.
"Better not to be too optimistic".
"Should North Korea take part, I believe the PyeongChang Winter Olympic Games will go beyond being a simple Olympic event to provide a great chance to contribute to peace between the South and North Korea and to peace in the entire Northeast Asian region", he said. "On Oct. 31, South Korea and China drew up guidelines of a sort that signify a new point of departure, but this can not be seen as a complete "agreement.' It's a makeshift agreement stating that China will decide on its position according to South Korea's attitude in the future". He arrived here Sunday following trips to Indonesia and Vietnam.
South Korean stocks traded 0.26 percent lower Tuesday morning, as investors awaited any signs of compromise in USA tax policy and economic data from China.
Trump held talks with Xi on Thursday, which led to the signing of business deals worth more than US$253 billion.