NYC siblings Sascha and Alexander Pinczowski among dead in Brussels terror attacks

At least two American citizens have been confirmed killed in this week's attacks in Brussels, a U.S. official says, as Secretary of State John Kerry is visiting the city to express his condolences to the Belgian people.

A family friend of siblings Sascha and Alexander Pinczowski issued a statement to the NY Daily News on Friday confirming their deaths.

“The Pinczowski family confirms that their children Sascha and Alexander died during the attacks in Brussels,” said Fans Van Herteren. “The family would like to express their gratitude for all the compassion and they now need time to grieve.”

Belgian authorities and the Dutch Embassy positively identified the remains of Alexander and Sascha Pinczowski.

That information was issued by James Cain on behalf of the Pinczowski family. Cain is the father of Alexander's fiancee, Cameron Cain. He says the family is "grateful to have closure on this tragic situation."

Speaking after meeting with Belgian Prime Minister Charles Michel, Kerry said the "United States is praying and grieving with you for the loved ones of those cruelly taken from us, including Americans, and for the many who were injured in these despicable attacks."

He did not give a specific number but a senior official said the families of two Americans had been informed of their deaths in Tuesday's attacks. The official, who was not authorized to speak to the matter publicly and spoke on condition of anonymity, did not have further details.

Dutch citizens Sascha and Alexander Pinczowski, who lived in New York, were last heard from at the Brussels Airport before the deadly terrorist bombings in the Belgian capital.

A Facebook post that appeared after the siblings were reported missing and asking for the public's help tracking them down had been removed Friday.