North Korea has celebrated the 84th anniversary of the Korean People's Army's founding without a major military event, the North's media reports showed Tuesday, amid tougher international sanctions.

The North marked its key military anniversary on Monday by holding cultural performances and other festivals across the nation, according to the Rodong Sinmun, the North's main newspaper.

Pyongyang celebrated the anniversary in a relatively calm manner without military events in the face of stronger United Nations Security Council sanctions over its nuclear and missile tests early this year.

North Korea usually holds big military events or parades during years when the final number of the year ends in a five or a zero.

There is growing speculation that North Korea may carry out another nuclear test or launch a medium- or long-range missile ahead of the ruling party's key congress slated for early May.

The Workers' Party of Korea  plans to hold the first congress in more than three decades early next month where the North will likely affirm the leader's tighter grip on power.

North Korea has ratcheted up its bellicose rhetoric against Seoul and Washington since early March in an apparent show of defiance against UNSC sanctions.

On Saturday, the North fired a submarine-launched ballistic missile in waters off its northeast coast, drawing international condemnation.

Last month, it test-fired what looked like an intermediate-range Musudan ballistic missile, though the launch ended in complete failure.

"North Korea appears to be strategically focusing on the preparation of the party congress," said Yang Moo-jin, a professor at the University of North Korean Studies. (Yonhap)