The 300-meter-tall, long-dormant hotel building that dominates Pyongyang's skyline has been lit up in the run-up to the anniversary of North Korea's founder Kim Il Sung's birth on Sunday, setting off speculation that it may finally open.

Locals have witnessed the glass-sheathed, pyramid-shaped 105-story Ryugyong Hotel be reanimated with lights since early April, which is, they say, often a sign in North Korea that a business is soon to start operating.

Construction of the hotel began in 1987, one of a number of projects thought to have been fueled by the country's rivalry with a fast-developing South Korea, host of the 1988 Olympics in Seoul. But financial constraints led to work being halted in the early 1990s.

In 2008, construction resumed with the help of investment from an Egyptian company.

But recently, the distinctive red, white and blue of the North Korean flag has lit up the hotel's imposing peak, with the edges of the building that is speculated to host more than 3,000 guest rooms also sparkling with multi-colored lights, indicating there might be more to come.