Li made the remarks during a meeting with South Korean President Moon Jae-in on the sideline of a series of leaders' meetings on East Asian cooperation in the Philippine capital of Manila.
It provided no details but China has been seeking to get relations with Japan and South Korea back on track after disputes over how to rein in North Korea's nuclear and missile programmes, and, in Japan's case, over the two countries' sensitive wartime history.
South Korea on Monday, November 13, said it is "determined" to bring its ties with the Association of Southeast Asian Nations (ASEAN) to "new heights" amid growing concerns over persistent threats from its neighbor North Korea.
He said differences in understanding between South Korea and China, North Korea's lone major ally, regarding the deployment of the U.S. Terminal High Altitude Area Defence (THAAD) system on South Koran soil had not been resolved.
"If talks begin to resolve the North Korea nuclear issue, I feel it will be realistically hard for North Korea to completely destroy its nuclear capabilities when their nuclear and missile arsenal are at a developed stage", Moon said in a briefing.
Also on Saturday, the US and South Korea launched a joint naval drill in a show of strength against the North's leader Kim Jong-un. But Japan, whose relations with both neighbors have often been fraught, appeared to make little progress toward its hopes of hosting a trilateral summit by the end of the year. "I believe we have created a chance to quickly normalize the countries' relationship through my talks with President Xi Jinping".
The South Korean president is set to return home Wednesday.
Speaking to reporters in the Philippines, Moon also said if North Korea agreed to talks, negotiations could be held with all options open although it was too early to say specifically what.
After the meeting, South Korea's presidential office said that the two nations would strengthen strategic dialogue and continue discussions next month when Moon was expected to visit China.