PYONGYANG, Korea, Democratic People's Republic Of -- While tensions between his country and the United States appeared to be escalating rapidly, North Korean leader Kim Jong Un made a high-profile appearance in Pyongyang on Thursday not to denounce Washington but to cut a ceremonial ribbon to mark the opening of a new high-rise district.

With more than 100,000 people gathered in a huge rally to mark the event, Kim stood front and centre on a red-carpeted stage to cut the ribbon.

The event was part of the run-up to the 105th anniversary of the birth of national founder Kim Il Sung, which falls on Saturday and is North Korea's most important holiday.

Nothing official has been announced, but a large-scale military parade is expected Saturday.

Tension in the region have risen with the dispatch of a U.S. aircraft carrier to the area and the deployment of thousands of U.S. and South Korean troops, tanks and other weaponry for their biggest-ever joint military exercises. Pyongyang has warned of war if it sees any signs of aggression from south of the Demilitarized Zone.

Life in the North's capital, however, has been outwardly quite normal over the past week, with residents turning out each day to prepare for their parts in mass events such as the parade, synchronized card displays or dancing parties in public plazas.

North Korea also has a history of connecting landmark construction projects to important political dates. The most recent previous example is another new street, Mirae Street, which was built in time for the 65th anniversary in 2015 of the founding of North Korea's ruling Worker's Party.

Pyongyang has invited a large contingent of foreign media to cover the events, and the modern and shiny new residential street is clearly one of the places they most wanted the foreigners to see.

Kim, who arrived in a black limousine, did not make a speech.

But North Korean Premier Pak Pong Ju said the project "incorporates the latest architectural science and technology, including solar and geothermal technology, and the greening of roofs and walls."

The sprawling development project also includes Pyongyang's tallest apartments, at 70 stories tall.

The buildings were put up in just over a year along what is called Ryomyong Street, which runs out of downtown Pyongyang, past North Korea's top university and down to the palace where the country's past leaders are kept embalmed.

The construction has gone on at breakneck speed, interrupted only by flooding in northeastern North Korea last autumn, when resources where temporarily diverted to reconstruction of homes there.