North Korea warned Thursday that it is on alert and will carry out “merciless military counter-actions” if the U.S. and South Korea provoke the Kim Jong Un-led country, according to the state-run Korean Central News Agency (KCNA). The comments come on the heels of an annual joint military drill conducted by Washington and Seoul in the Korean Peninsula Wednesday.

The military exercises, called the Foal Eagle, will continue until the end of April and the South Korean defense ministry said a computer-simulated command post exercise known as Key Resolve will begin on March 13. Moreover, the U.S. will reportedly send strategic assets, including aircraft carriers and military vehicles to participate in the drills. The USS Carl Vinson aircraft carrier and the B-1B and B-52 bombers will also be part of the drills.

“Lots of U.S. war operation groups and nuclear strike means deployed in South Korea and in its vicinity have already begun moving to the positions for invasion of the North,” the General Staff Department of the Korean People's Army said in a statement, according to KCNA.

“Should the U.S. imperialists and the South Korean puppet forces fire even a single shell into the waters where the sovereignty of our Republic is exercised, the KPA will immediately launch its merciless military counter-actions.  They should not forget that our revolutionary armed forces have everything in place and are always on alert,” the statement read.

Furthermore, the General Staff also warned that the North Korean army "will counter them with the toughest counteractions as it had already declared. This stand of ours clarified before the world is by no means an empty talk."

Tensions in the Korean Peninsula — a region that has always been restive — were aggravated after Pyongyang carried out a missile test in February. It has been also blamed for violating global nuclear weapons treaties with its ballistic missile tests.

Last month, the South Korean defense ministry warned that Pyongyang has "thousands of tons of chemical weapons" across the country. It also called for invoking the Chemical Weapons Convention and taking "collective measures" to tackle Pyongyang’s growing threat.