A US nuclear-powered aircraft carrier has entered the international waters of the East Sea, informed sources said Tuesday, in an apparent show of America's military might amid concerns over possible North Korean provocations.

The USS Abraham Lincoln strike group is currently in waters east of South Korea's southeastern city of Ulsan -- the first such maneuvers in the waters since late 2017, when tensions remained high due to Pyongyang's saber-rattling.

The carrier group is expected to be in the East Sea for three to five days, the sources said.

The US Naval Institute also confirmed on its website that the carrier strike group is in the East Sea.

Speculation has persisted that the North could engage in provocative acts like the launch of an intercontinental ballistic missile (ICBM) or a nuclear test in time for its major political events later this month.

The North is set to celebrate the 110th birth anniversary of its late founding leader Kim Il-sung on Friday and the founding anniversary of the North Korean People's Revolutionary Army on April 25.

In November 2017, the US sent three flattops -- USS Ronald Reagan, USS Nimitz and USS Theodore Roosevelt -- to the East Sea operational area, called the Korea Theater of Operations (KTO), in an unprecedented display of force against North Korea. (Yonhap)