SEOUL – North Korea said Friday it had test-fired strategic cruise missiles to demonstrate its nuclear counter-attack capability, days after it vowed to respond to what it called escalating U.S.-led hostilities since the start of the Trump administration.

The official Korean Central News Agency said leader Kim Jong Un oversaw the missile tests off the country’s west coast Wednesday. They were the North’s fourth missile launch event this year and the second of President Donald Trump’s second term.

The launches were designed to inform “the enemies, who are seriously violating our security environment and fostering and escalating the confrontation environment,” of the North Korean military’s counterattack capability and the readiness of its nuclear operations, KCNA said.

Kim expressed satisfaction over the results of the drills and said the military must be fully ready to use its nuclear weapons, the report said.

South Korea’s Joint Chiefs of Staff said in a statement later Friday that it had detected and tracked the North Korean launches. It said the South Korean military maintains readiness to repel any potential provocation by North Korea based on the solid South Korea-U.S. military alliance.

Since his Jan. 20 inauguration, Trump has boasted of his summitry with Kim during his first term and said he would reach out to Kim again. North Korea hasn’t directly responded to Trump’s overture as it continues its typical aggressive rhetoric against the U.S. and weapons testing activities.

Many experts say Kim, now preoccupied with his support of Russia’s war against Ukraine with supply of weapons and troops, won’t likely embrace Trump’s outreach anytime soon. They say Kim could reconsider if he doubts he’ll maintain North Korea’s current solid cooperation with Russia after the war ends.

Last Saturday, North Korea’s Defense Ministry alleged the U.S. and its allies were ramping up more serious military provocations targeting North Korea since Trump took power. It cited the recent U.S.-South Korean aerial exercise involving a U.S. B-1B bomber and other reported activities involving U.S. military assets. A Defense Ministry statement said North Korea will counter the strategic threat of the U.S. with strategic means.

Kim and Trump met three times from 2018-19 to discuss the fate of North Korea’s nuclear program, but their diplomacy derailed due to disputes over U.S.-led sanctions on the North. Kim has since sharply increased the pace of weapons tests to expand and modernize his nuclear arsenal. Having a bigger nuclear arsenal now, experts say Kim would think he could win greater U.S. concessions if he revives diplomacy with Trump.