South Korea's President Lee Jae Myung is set to meet Chinese leader Xi Jinping as he seeks to reset frayed ties with his country's biggest trading partner. Regional security and Beijing's unofficial ban on Korean pop culture are also on the agenda for Monday's meeting, which is their second summit since November, when Xi visited South Korea.

The South Korean leader hopes to secure pledges to expand economic cooperation with China, his country's largest trading partner.

Lee’s visit is positive sign for China-South Korea relations. But both sides must heed the lessons from the THAAD dispute.