The North Korean government underlined its anger at joint U.S.-South Korean war games on Monday by firing two short-range ballistic missiles into the sea, Agence France-Presse reported.

Pyongyang always protests the annual drills and warned of "merciless" retaliation on Monday; nevertheless, the regime of dictator Kim Jong-Un seemed to strike a particularly angry note this year, North Korea watchers noted.

Jeung Young-Tae, an analyst at the South Korean Institute for National Unification, said the threat could easily turn into a more serious confrontation.

"If there is a particularly sharp escalation, we could see the North orchestrating some kind of clash on the maritime border," Jeung said.

The missile launches were accompanied by a warning from the North Korean armed forces that this year's military exercises would bring the peninsula "toward the brink of war." The devices were fired from the western port city of Nampo and fell into the sea off the nation's east coast, South Korea's defense ministry reported.

Kim Min-Seok, a spokesman for the ministry, suggested Pyongyang may actually be intent on triggering a "security crisis."

"If North Korea takes provocative actions, our military will react firmly and strongly so North Korea will regret it in its bones," Min-Seok said, according to Reuters.

An unnamed spokesperson for the U.S. Department of State, meanwhile, said missile launches represent a threat to peace and called on North Korea to "refrain from provocative actions that raise tensions."

Similarly, the Japanese government claimed the actions posed a serious threat to safety at sea and in the sky.

"The ballistic missile launches by North Korea are extremely problematic conduct in terms of aviation and navigation safety," Chief Cabinet Secretary Yoshihide Suga said. "We swiftly lodged a stern protest with North Korea."

North Korea's leader, meanwhile, reportedly told the army to train to "tear to pieces the Stars (and) Stripes," a reference to the American flag, Fox News noted. Kim was speaking at the opening a new hall at the Victorious Fatherland Liberation War Museum in Pyongyang, according to KCNA.