The United States is a "hard target" but "tasty target" for extremists despite the difficulties presented by geography and the American counterterrorism apparatus put in place after the Sept. 11, 2001, attacks, a former Homeland Security Department official said Tuesday.
The deadly terrorist bombing on Monday night after an Ariana Grande concert in Britain shows how motivated terrorists are to carry out attacks, Jack Tomarchio said on CNBC's "Squawk Box." He was principal deputy undersecretary of Homeland Security for intelligence during George W. Bush's presidency.
"It's a chess game," Tomarchio said. Terrorists are always looking for weaknesses and ways to thwart security measures, he added.
Children were among 22 people killed in Monday night's suicide attack at Manchester Arena, near one of the venue's exits as the Grande concert was ending. Fifty-nine people were wounded. British police said they arrested a 23-year-old man in connection with the bombing. The Islamic State terror group has claimed responsibility.
The U.S. cannot get complacent believing these types of attacks can only happen in Europe, said Tomarchio, currently president of international strategic consultancy Agoge Group.
American remains the "big ticket target" for terrorism, he said. "We're a little harder to get to" but make no mistake terrorists want to strike the U.S., he warned.
President Donald Trump has "done a good job frankly, touching into the compassion that's needed" after the bombing, Democratic former Sen. Max Baucus from Montana said in a separate CNBC interview.
Trump has also "done a good job" to highlight efforts to stop terrorism, said Baucus, a former U.S. ambassador during the Barack Obama administration.
Speaking after meeting with Palestinian leader Mahmoud Abbas in Bethlehem on Tuesday, Trump blamed "evil losers" for the Manchester attack, adding the world "cannot stand for a moment longer for the slaughter of innocent people."