Story highlights U.S. and Iraqi officials fear dam could fail "with little warning'

If the dam failed, Mosul -- with a population of 600,000 -- would flood in four hours

(CNN) The largest dam in Iraq is facing an "unprecedented risk of catastrophic failure with little warning," prompting a "chilling" meeting at the United Nations Wednesday morning.

The failure of the Mosul Dam, located in northern Iraq, has been a concern for Iraqi and American officials for years.

But the meeting hosted by Samantha Power, U.S. ambassador to the United Nations, and Mohamed Alhakim, Iraqi's U.N. ambassador, highlighted the seriousness of inaction and called on the international community to pay attention to "urgently-needed repair work," Power said.

Millions could be at risk

The Mosul Dam is a two-mile-long barrier that can hold back as much as 441 million cubic feet of water, according to Engineering News-Record, a construction industry website. If breached, 500,000 to 1.47 million Iraqis living in the flood path would be at serious risk, according to the readout of Wednesday's briefing.

Just left chilling briefing on Mosul dam in Iraq; failure could leave Mosul City under 15m of water in only hours. pic.twitter.com/FqJuC4SiVy — Samantha Power (@AmbassadorPower) March 9, 2016

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