SEOUL/WASHINGTON — North Korea fired two short-range ballistic missiles off its east coast earlier today, South Korea's Joint Chiefs of Staff (JCS) said, the second such launch in less than a week.

The first missile was launched at 5:06 am, and the second at 5:27 am, from the Kalma area near the North's eastern port of Wonsan, according to the JCS.

Both are estimated to have flown about 250 kilometres at an approximate altitude of 30 km, the JCS said, adding that the South Korean and US militaries are analyzing more details.

Defense Minister Jeong Kyeong-doo said the missiles were identified as a different type from previous models launched by North Korea, but did not elaborate.

The launches come six days after North Korea fired two short-range ballistic missiles from the same area into the East Sea/Sea of Japan in its first provocation since May. Those missiles flew some 600 kilometres and were identified as "KN-23," or the North's version of Russia's Iskander ballistic missile.

"Successive missile launches by North Korea are not conducive to efforts to reduce tensions on the Korean Peninsula and we call for a halt to these acts," the JCS said in a statement.

After last week's missile firings, the North's state media said that the launches were designed to send a "solemn" warning to South Korea over its plan to conduct joint military drills with the US next month and purchase high-tech fighter jets from the ally.

Following the latest launches, South Korea defense minister Jeong said that North Korea should be regarded as an "enemy" if it carries out provocations that threaten South Korea.

The United States responded cautiously.

"We are aware of reports of a missile launch from North Korea, and we will continue to monitor the situation," a State Department spokesperson told Yonhap News Agency on condition of anonymity.

The series of launches comes as Washington has sought to restart working-level talks on dismantling the North's nuclear and ballistic missile programs in line with an agreement reached when US President Donald Trump and North Korean leader Kim Jong-un held a surprise meeting at the inter-Korean border last month.

Despite last week's missile launches, the US has remained upbeat about the prospects for talks with the North, with Trump dismissing last week's missiles as "smaller ones" that many countries test. US Secretary of State Mike Pompeo also said on Monday he hoped the discussions will resume "very soon."

Pompeo also described last week's launches as a negotiating tactic that allowed the talks to move forward. While noting the US commitment to diplomacy, the State Department urged North Korea to refrain from further "provocations."

Trump insisted earlier Tuesday that he has a good relationship with Kim.

"My relationship with Kim Jong-un is a very good one, as I'm sure you've seen," he told reporters at the White House. "We'll see what happens. I can't tell you what's going to happen."

The North has also renewed its commitment to talks.

According to US news reports, North Korean and US officials held a secret meeting at the truce village of Panmunjom last week, where the North Koreans expressed a willingness to resume working-level nuclear talks very soon.

UN Security Council resolutions ban North Korea from launching ballistic missiles. — YONHAP