(CNN) For months, North Korea has been preparing a massive display of national unity and military might to mark the 70th anniversary of the country's founding.

International journalists have been invited to watch a military parade as it weaves through the capital Pyongyang on Sunday, a torch-lit rally and the Mass Games, a highly choreographed event expected to involved hundreds of thousands of people.

The Mass Games are making a comeback after a five-year hiatus, for reasons that are unclear. It's not a competitive event but a distinctly North Korean piece of performance art similar in size and scale to an Olympic opening ceremony.

North Korea is known for signaling its future intentions and policies by indirect and sometimes opaque methods, so experts will be watching events closely for insight into what leader Kim Jong Un and his top aides are thinking -- especially as negotiations with the US over North Korea's nuclear arsenal appear to have reached a deadlock.

"These milestone anniversaries are an opportunity to give the people something to celebrate, instill a sense of pride and they're also an opportunity to send a message to the outside world," said Jean Lee, the director of the The Wilson Center's Korea Center and a former Pyongyang bureau chief for The Associated Press.

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