South Korea is poised to respond to additional missile launches after North Korea fired several short-range “projectiles” into the sea off its eastern coast.

The South Korean military issued a statement that the projectiles launched Saturday flew up to 125 miles before splashing into the sea.

The South has bolstered its surveillance, and is working with the US to analyze the weapons, the Associated Press reported. If they find that the North fired banned ballistic missiles, it would be the first such launch since November 2017.

That year, President Donald Trump and North Korean Leader Kim Jong Un were lurching toward possible war, but tensions cooled and the two met for the first time in Singapore last year, with a vague agreement promising “denuclearization” the result.

A second meeting in Vietnam earlier this year was less successful. Some see the latest missiles as a sign of Pyongyang’s growing frustration at the stalled talks with Washington meant to provide coveted sanctions relief in return for nuclear disarmament.

Experts say the North may increase these sorts of low-level provocations to apply pressure on the United States to agree to reduce crushing international sanctions.

White House Press Secretary Sarah Sanders said in a statement that the United States was aware of North Korea’s actions and would continue to monitor the situation.

With Post wires