North Korea’s latest provocation appears to have alarmed South Korea’s dovish leadership.

After North Korea successfully tested Friday its second intercontinental ballistic missile in a month, senior leaders in Seoul contacted their counterparts in Washington to discuss the possibility of boosting South Korea’s offensive and defensive weapons systems, according to the New York Times.

Friday’s missile test demonstrated capabilities initially believed to be beyond North Korea. As North Korea’s programs are progressing faster than expected, South Korea has decided to increase the payload of its long-range ballistic missiles and deploy additional Terminal High Altitude Area Defense (THAAD) anti-missile units. South Korean leadership is determined to start negotiations with the U.S. on these issues immediately.

According to the terms of a bilateral treaty, South Korea is allowed to build missiles with ranges of 800 kilometers, but they cannot carry a conventional warhead weighing more than 500 kilograms. South Korea wants to mount a warhead weighing roughly one metric ton on its new Hyunmoo II ballistic missiles, which can range all of North Korea. The South Korean government brought the issue up in a summit meeting last month with plans to discuss it in greater detail later.

North Korea’s latest provocations has added a sense of urgency to the situation.

Enhanced missiles with heavier warheads will allow the South Korean military to penetrate North Korea’s hardened defenses in the event of a conflict.

Not only does South Korea want the ability to strike North Korea, but it also wants the ability to intercept incoming missiles.