House Speaker John Boehner expressed confidence today that whoever carried out the Boston Marathon attack Monday will be brought to justice, even though officials still don't know who was responsible for the twin bombings.

"Obviously, we want to know who did this and why was it done," Boehner, R-Ohio, told reporters this morning. "We don't know who perpetrated this or for what reasons but I'm confident that we'll get to the bottom of it."

A House Intelligence Committee meeting that was scheduled for this morning was postponed, although members of the House are expected to attend a previously scheduled closed-door briefing later today on cybersecurity with Secretary of Homeland Security Janet Napolitano, National Security Agency Director Keith Alexander and FBI Director Robert Muller III.

Rep. Mike McCaul, the chairman of the House committee on Homeland Security, Monday night called the event "an act of terrorism."

Boehner acknowledged today that "it was a terrorist attack of some sort," but he emphasized that early intelligence is too incomplete to know how to describe it.

"Until we know who or why, I don't think we can further define it," Boehner said. "There's just not enough information at this point in time.

"We just don't know enough about it but I have no doubts that we will. Not one doubt," he added. "The president and I had this conversation last evening. He'd like to know more, I'd like to know more and the American people would like to know more. Unfortunately we don't, but I am confident we're going to get to the bottom of this."

Despite recent budget cuts across the federal government, Boehner said he believes counterterrorism officials are adequately equipped and Congress does not need to provide additional tools to authorities in order to track down the perpetrators.

"Our law enforcement officials, both at the federal level and the local level, are going to have all the resources they need and technology and tolls that they need to get to the bottom of this," Boehner said. "We know we're vulnerable. It's talked about almost every day, but this is a reminder just how vulnerable. We really are in this era of what I'll call 'modern warfare.'"

Boehner, who ordered that flags be flown at half-staff at the Capitol, paid tribute to the victims and their families, professionals and good Samaritans "who helped prevent further loss of life."

"I don't think words can express our sorrow for the families that are grieving today as a result of what happened in Boston," he said. "It's a terrible day for all Americans, but we carry on in the American spirit. We'll come together with grace and with strength."