Amid North Korea’s growing nuclear and missile threats, Seoul and Washington will explore the possibility of additional sanctions and other ways to deter another major provocation during their summit next week, the U.S. ambassador here said Thursday.

Mark Lippert, however, ruled out a stationing of advanced U.S. missile defense assets on the peninsula as an item on the agenda for Presidents Park Geun-hye and Barack Obama, though she is scheduled to visit the Pentagon during her trip accompanied by Defense Minister Han Min-koo.

“But back to principle, we would like North Korea not to undertake any kind of actions that would violate U.N. Security Council resolutions in the first place, and that’s what we’re working on right now,” the envoy said in a joint interview at his residence in central Seoul. 

Tension has been flaring in recent weeks as Pyongyang threatened to launch a long-range rocket and extend what it calls nuclear deterrence ahead of the 70th anniversary of the founding of its ruling Workers’ Party on Saturday.

The North’s evolving missile threats have helped prompt the U.S. Forces Korea to carry out a site survey for a possible deployment of the Terminal High-Altitude Area Defense system, which is designed to shoot down short, medium- and intermediate-range ballistic missiles in their terminal stage.

While North Korea is to feature “robustly and deeply,” the two leaders will focus on a “three-pronged strategy” consisting of diplomatic efforts, economic sanctions and measures as well as robust defense and deterrence, Lippert said.

He also called on the Kim Jong-un regime to engage in “authentic and credible” talks to break the prolonged standoff and deepening isolation, citing recent Washington’s breakthroughs with Iran, Cuba and Myanmar.

“(They were) instances where there have been serious, incredible interlocutors on the other side of the table willing to negotiate in principled diplomacy. The Obama administration has reciprocated and come to conclusions on negotiations with three countries that historically have had very difficult relationships,” the ambassador said.

“North Korea doesn’t seem interested in engaging with other countries. … So I think the ball is in their court.”

On the economic front, Lippert struck an upbeat tone about Seoul’s potential membership in the recently concluded Trans-Pacific Partnership, welcoming its interest and reaffirming Washington’s willingness for related discussions.

The two presidents will also seek to reinforce the partnership on “new frontiers” ― emerging nonconventional security challenges such as cyberspace, environment, energy and global health, he noted.

“(South Korea) has bilateral free trade agreements with 10 of the 12 members of the TPP so it puts them in a logical position, good position going forward,” he added.

“We have long welcomed their interest in the TPP and look forward to continue conversations with them.”

By Shin Hyon-hee (heeshin@heraldcorp.com)