WASHINGTON—White House national security adviser Robert O’Brien has cut short a multicountry trip to Europe to return to the U.S. to address the suspected Russian hack of government agencies, signaling growing alarm within the Trump administration about a cyber espionage campaign considered potentially one of the most damaging in years.
The change of plans for Mr. O’Brien comes two days after it was disclosed that multiple federal agencies had been hacked as part of a global hacking campaign that is believed to have also ensnared private corporate networks across the globe.
“Ambassador O’Brien is returning to address the hacking incident,” John Ullyot, a spokesman for the National Security Council, said in a statement. Mr. O’Brien will hold meetings Tuesday evening and Wednesday morning and convene “a high level interagency meeting” this week, Mr. Ullyot said.
Mr. O’Brien had been scheduled to return Saturday after planned stops in Italy on Tuesday and visits later in the week to Germany, Switzerland and the U.K. He had already met with Prime Minister Benjamin Netanyahu in Israel and President Emmanuel Macron in France.
The hack continued for months, largely undetected by the Trump administration and cybersecurity firms, until the past week, according to people familiar with the matter. Current and former officials and cybersecurity experts have described the hack as an espionage operation rather than one aimed at damaging computer networks, and said it represents a significant counterintelligence failure.
