He has also indicated that he would seek a review of the deployment of a U.S. missile system to the country.
THAAD - or Terminal High-Altitude Area Defence - refers to the U.S. missile defence system deployed in South Korea to counter threats from the North, but which China fears will undermine its own military capabilities.
Lee earlier said Moon had sent him to China to keep communications open "at a critical time".
Lu Chao, an expert on Korean studies at the Liaoning Academy of Social Sciences, told the Global Times that the new South Korean administration shouldn't expect bilateral ties, especially economic cooperation, to return to pre-THAAD status, if it can not sweep away the anti-missile system. A separate meeting could also be possible in August.More news: TPP countries to assess options
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"Since past year, the bilateral relationship has suffered an undeserved frustration, which we are not willing to see", Wang told Lee in his opening remarks.
"We're now at a crossroads in our relations", Wang told Lee and urged the new Korean administration to "remove the obstacles" that stand in the way of better ties - a broad hint at the THAAD battery. "We believe South Korea will bring clear measures to improve relations".
Lee said the ROK understands China's concerns and is willing to make efforts to properly solve relevant issues.
"When Hwang traveled to China in late June, Chinese President Xi Jinping proposed having discussions through various channels on the THAAD issue in a way that wouldn't harm either side's interests".
Moon's special envoy to Washington Hong Seok-hyun, a former ambassador to the United States, was also named as a special presidential aide on diplomacy and security.
South Korea's special envoy to Russia, Song Yong-gil, who's a lawmaker from the ruling Democratic Party of Korea, left for Moscow on Monday.