According to South Korea’s military, North Korea fired three ballistic missiles Monday morning towards the Sea of Japan. The missiles were fired from areas in close proximity to the Hwanghae province, South Korea’s military said in a statement.

South Korea’s Joint Chiefs of Staffs have identified them as Rodong missiles, which have a range of 1,000 kilometers. Japan’s Defense Ministry says the rockets fell into its Exclusive Economic Zone in the region, known in Korea as the East Sea.

North Korea has conducted a series of missile tests this year in defiance of U.N. sanctions imposed after its fourth nuclear test in January.

“This launch is a clear act of provocation not only to our country, but to the international community considering the timing of its launch coinciding with the G-20 summit held in China’s Guangzhou today,” said Japanese cabinet secretary Yoshihide Suga.

The occurrence came at a slightly awkward time, as North Korea’s only real ally, China, is currently hosting the G20 summit in Hangzhou. A few mere hours before the missiles were launched, South Korean President Park Geun-hye and Chinese President Xi Jinping met on the sidelines of the summit.

In a statement, the US said it “strongly condemns” the launches.

The launches also came hours after Chinese President Xi Jinping told his South Korean counterpart at the G20 summit that Beijing opposes the deployment of the United States’ THAAD missile defense system to South Korea.

“Mishandling the issue is not conducive to strategic stability in the region and could intensify disputes,” Xi was quoted as telling Park Geun-hye, according to a report from China’s official Xinhua News Agency.

“Today’s reckless launches by North Korea threaten civil aviation and maritime commerce in the region,” State Department spokesman John Kirby stated on Monday.

“We will raise our concerns at the UN about the threat posed to international security by these programs,” he added. “We will also do so in other fora — including the upcoming East Asia Summit — to bolster international resolve to hold the DPRK accountable for its provocative actions. Our commitment to the defense of our allies in the face of these threats remains ironclad.”