The U.S. ambassador to South Korea called on North Korea Tuesday to change its stance on the nuclear issue, saying Washington remains open to talks with Pyongyang, lawmakers here said.
  

In a breakfast meeting with a group of lawmakers from both ruling and opposition parties, Mark Lippert said North Korea cannot simultaneously pursue a nuclear weapons program and economic development and that the North should return to the multilateral denuclearization talks or face continued sanctions and isolation, according to participants.
  

Lippert said Pyongyang will face growing costs if it continues to stick to the nuclear weapons program, they said.
  

His remarks came as the U.S slapped fresh sanctions on North Korea earlier last month following its suspected hacks on Sony Pictures over a comedy film about assassinating North Korean leader Kim Jong-un.
  

The U.S. has said that it seeks a two-track strategy of pressure and dialogue when it comes to North Korea.
  

Sung Kim, Washington's top nuke envoy, had offered to meet with North Korea's top nuclear negotiator in a third country, but the proposed meeting did not take place as the North insisted on a meeting in Pyongyang, according to a diplomatic source.
  

Lippert also reiterated the U.S. government's stance that there is no daylight between the U.S. and South Korea in dealing with North Korea, according to the lawmakers.
  

There are lingering concerns here that Washington's tough stance on North Korea may be at odds with Seoul's initiative for dialogue with Pyongyang.
  

The U.S. envoy said that strengthening security or deterrence is the basis for the strong alliance between Seoul and Washington.
  

Lippert also expressed hope that he can play the role of a bridge to herald the Korean culture to the world by visiting many cultural remains placed on the UNESCO world heritage list, according to participants. (Yonhap)