Updated

North Korea vowed to bolster its defenses to protect itself against airstrikes similar to the ones President Donald Trump ordered on Friday against a Syrian airbase.

North Korea called the strikes "absolutely unpardonable,” saying they prove its nuclear weapons are justified to protect the country against Washington's "evermore reckless moves for a war."

The comments were made by a Foreign Ministry official and carried Sunday by North Korea's state-run Korean Central News Agency. The official spoke under anonymity, which is common in KCNA reports.

Advisers said Trump was outraged by heartbreaking images of young children who were among the dozens killed in the Syrian chemical attack and ordered his national security team to swiftly prepare military options.

Trump made it a point to address the media about the Syria strike at his Mar-a-Lago resort in Florida just moments after dining with his Chinese counterpart President Xi Jinping.

Trump has said that if China doesn't exert more pressure on North Korea, the United States will act alone.

The immediate focus after the strikes was on Russia’s reaction, which was not happy with the strikes and spoke in defense of Syria. The attention has since shifted on to the next move by North Korean leader Kim Jong-Un.

"Some forces are loud-mouthed that the recent U.S. military attack on Syria is an action of warning us but we are not frightened by it," the report said, adding that the North's "tremendous military muscle with a nuclear force as its pivot" will foil any aggression by the U.S.

"We will bolster up in every way our capability for self-defense to cope with the U.S. evermore reckless moves for a war and defend ourselves with our own force," it said.

North Korea considers Syria an ally. But unlike Syria, experts warn that North Korea has a means of striking back if provoked.

Tensions have been higher than usual because the annual war games between the U.S. and South Korean militaries are underway. The exercises this year are the biggest ever and have included stealth fighter training and other maneuvers that are particularly sensitive to North Korea.

On Saturday, President Donald Trump and South Korea's leader, acting President Hwang Kyo-Ahn, spoke by phone. The White House said the two agreed to stay in close contact about North Korea and other issues.

The Pentagon announced on Saturday that a Navy carrier strike group was moving toward the western Pacific Ocean to provide a physical presence near the Korean Peninsula.

North Korea's recent ballistic missile tests and continued pursuit of a nuclear program have raised tensions in the region, where U.S. Navy ships are a common presence and serve in part as a show of force.

Along with its rapidly advancing nuclear and long-range missile capabilities, North Korea has its artillery and short-range missiles trained on Seoul, the capital of U.S. ally South Korea.

The Associated Press contributed to this report.