South Korea says its president will hold summit talks next week with Chinese President Xi Jinping to try to improve ties strained over the deployment of a U.S. missile-defense system.

Senior presidential official Lee Sang-chul told a televised briefing Tuesday that President Moon Jae-in and Xi will talk on the sidelines of an annual regional forum in Vietnam next week.

Lee says the agreement is part of efforts by the two countries to put bilateral ties on a normal track.

In response to the missile-defense system's deployment, China has issued angry rhetoric and South Korean businesses operating in China have suffered economic retaliation.

China believes the system poses a threat to its own security. Seoul and Washington say it is purely aimed at defending South Korea against North Korean threats.