Update: They were siblings.
The family of two New York City siblings has confirmed that authorities confirmed they died in the bombings in Brussels.
Belgian authorities and the Dutch Embassy positively identified the remains of Alexander and Sascha Pinczowski.
The information was issued Friday by James Cain on behalf of the Pinczowski family. Cain is the father of Alexander's fiancé, Cameron Cain.
He says the family is "grateful to have closure on this tragic situation."
The siblings were on the phone with a relative at Brussels airport when the phone went dead.
They were Dutch nationals, according to officials in the Netherlands, but both apparently had lived in the U.S. for some time.
As of Thursday, there were still a number of Americans missing after the terror attacks in Brussels. Friday morning, however, a U.S. official confirmed that at least two of those missing were killed. Their names have not yet been released.
[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.
Secretary of State John Kerry flew to Brussels Friday morning to express his condolences. He also discussed the urgency of fighting the Islamic State.
"The United States stands firmly with Belgium and with the nations of Europe in the face of this tragedy," Kerry said.
"We—all of us representing countless nationalities—have a message for those who inspired or carried out the attacks here or in Paris, or Ankara, or Tunis, or San Bernardino, or elsewhere: We will not be intimidated," he added. "We will not be deterred. We will come back with greater resolve - with greater strength - and we will not rest until we have eliminated your nihilistic beliefs and cowardice from the face of the Earth."