PANMUNJOM, Korea — Gen. Vincent Brooks expressed hope Thursday for “continued dialogue and coordination” with North Korea as he made his first trip to the heavily militarized border since taking command of U.S. Forces Korea.

The Demilitarized Zone, which is lined with barbed wire and landmines, was a stark reminder for Brooks of the challenges in dealing with a country that is eagerly pursuing nuclear weapons — and missiles capable of reaching the U.S. mainland — and has threatened to use them.

Brooks toured the area with Gen. Lee Soon-jim, chairman of the South Korean joint chiefs of staff, who urged him to “maintain the utmost readiness posture.” The two made remarks as they peered toward North Korea from hilltop Observation Point Ouellette, about 25 yards from the demarcation line that divides the peninsula.

Tensions have risen since North Korea staged its fourth underground nuclear test and a long-range rocket launch earlier this year. The international community reacted by slapping the isolated nation with a new round of tough U.N. economic sanctions.

Brooks previously served as a battalion commander in the 2nd Infantry Division near the DMZ, but Thursday’s trip was his first battlefield circulation since taking the helm of USFK from Gen. Curtis M. Scaparrotti last month. Brooks is also in charge of the U.N. Command and the South Korea-U.S. Combined Forces Command.

The U.S. has about 28,500 troops in South Korea, which remains technically at war with the North after the 1950-53 conflict ended with an armistice instead of a peace treaty.

“I’ve been to this outpost many times over the years, and each time I come back, I’m reminded of how quickly things can change on the Korean peninsula and why it is that we must remain ready all the time and remain strong,” Brooks said.

“But I’m also reminded that we’re in the military armistice-controlled area and that there is a need for continued dialogue and coordination, and we look forward to the time that that can resume again.”

North Korean leader Kim Jong Un said earlier this week that his country would use nuclear weapons only in self-defense. He also said he would try to normalize relations with “hostile” nations and called for talks with South Korea.

Six-party talks involving the United States, China, Japan, Russia and the two Koreas, which were aimed at resolving the long-running nuclear crisis, broke down in 2009.

South Korea has dismissed the call for talks, saying the North has not shown a sincere intent to denuclearize. The U.S. has repeatedly insisted that Pyongyang give up its nuclear ambitions.

The two generals also met with soldiers at the Joint Security Area, standing between two blue meeting houses that straddle the demarcation line. It is the only part of the zone where North and South Korean forces stand face to face.

“In this position I am certainly committed to maintaining the strength of the alliance while also trying to protect the strength of the armistice as well as we can,” Brooks said.