Iraq's new prime minister, Haider al-Abadi, warned that ISIS fighters were plotting to attack subway systems in undisclosed American cities as well as the Paris metro. Though he did not provide any concrete information on what would happen or when, al-Abadi said Iraqi intelligence had uncovered the plot. U.S. security officials have rejected the allegations.

Speaking with journalists at the United Nations, where world's heads of state are meeting, Prime Minister al-Abadi said ISIL fighters were planning to attack underground transport systems in the U.S. and France, according to CBS News. He cited information given to him by Iraqi intelligence, which captured and interrogated ISIL fighters. He explained the suspects were believed to be French and American nationals fighting in Iraq alongside ISIL.

"Today, while I'm here I'm receiving accurate reports from Baghdad that there were arrests of a few elements and there were networks from inside Iraq to have attacks ... on metros of Paris and U.S.," al-Abadi told reporters. "They are not Iraqis. Some of them are French, some of them are Americans. But they are in Iraq."

When reporters asked if the attacks had been thwarted, he said, "No, it has not been disrupted yet. ... This is a network." Then, when asked if he knew when the attacks would happen, he said, "I'm not sure."

In response to this news, the New York governor, Andrew Cuomo, said the state is acting with "the utmost precaution," according to The Associated Press. Just the previous day, both Governor Cuomo and New Jersey Governor Chris Christie had raised security in their states.

However, it may all be for naught. NBC News reports that U.S. government officials have found no proof of what the Iraqi prime minister said. Though there had been a threat a month ago against commuter trains in the New York City area, the FBI, NYPD, MTA and Port Authority Police did not find a specific plot.

"We take any threat seriously and always work to corroborate information we receive from our partners," National Security Council spokeswoman Caitlin Hayden said.

President Obama introduced an anti-terrorism resolution to the U.N. Security Council, which passed unanimously and aims to counter violent extremism through the cooperation of nations.