President Xi Jinping said on Tuesday that China and South Korea should promote their strategic cooperative partnership to a higher level.

He made the call over the phone with South Korean President Lee Jae-myung.

China and South Korea should inject more certainty into the regional and international landscapes, Xi said, adding that the two countries should jointly safeguard multilateralism and free trade and ensure stable global and regional industrial and supply chains.

"A healthy, stable and continuously deepening China-South Korea relationship aligns with the trend of the times," the president said.

Xi added Beijing and Seoul should respect each other's core interests and concerns, and the two countries should deepen people-to-people and cultural exchanges.

The call came after South Korea's new centre-left leader was elected in a landslide last week after winning a snap election triggered by his predecessor's disastrous martial law declaration.

Seoul has long trod a fine line between top trading partner China and defence guarantor the United States.

Relations with Beijing suffered under Lee's predecessor Yoon Suk-yeol, who cleaved close to the United States and sought to improve ties with former colonial master Japan.

But both countries' export-driven economies have now found themselves in the crosshairs of US President Donald Trump's tariff blitz. (Xinhua/AFP)