Lockheed Martin's logo is seen during Japan Aerospace 2016 air show in Tokyo, Japan, October 12, 2016. REUTERS/Kim Kyung-Hoon

WASHINGTON (Reuters) - Lockheed Martin Corp LMT.N, the Pentagon's No. 1 weapons supplier, said on Tuesday its customers want to defend themselves against possible incoming missile attacks and are increasingly asking about missile defense systems.

The greater interest comes amid a surge of North Korean long-range missile tests, unsettling its neighbors South Korea and Japan, as well as the United States.

“The level of dialogue around missile defense is now at the prime minister and minister of defense level,” Tim Cahill, the vice president of Lockheed’s Air and Missile Defense business, told Reuters in an interview.

U.S. President Donald Trump on Tuesday said: “North Korea best not make any more threats to the United States. They will be met with fire and fury like the world has never seen.”

Some countries are putting missile defense at the top of their list of desired capabilities, Cahill said. Interest has increased over the last 12 to 18 months, as have threats, he said.

Shares of Lockheed are up nearly 8 percent, to $300.10, since North Korea’s first long-range missile test on July 4. The stock is up 20 percent year-to-date.

The increased demand could turn into sales over the coming years. The U.S. government sanctions weapons sales in a process that can take years and often requires the approval of U.S. legislators.

Lockheed sells security and intelligence products including ships, planes, and missile systems to the U.S. intelligence community, the military and NASA. The U.S. government accounted for about 70 percent of Lockheed’s revenue in 2016. The company has been working to grow its international customer base, which accounted for 27 percent of revenue last year.