WASHINGTON -- US President Donald Trump said on Wednesday a major federal investigation was underway to probe the suspicious packages sent to former President Barack Obama, the Clintons, CNN offices and others.

Speaking at the White House, Trump said he was briefed by federal authorities on those suspicious package attacks and promised "the full weight of our government is being deployed" to investigate.

"Acts and threats of political violence have no place in the United States of America," he said. "We're extremely angry, upset, unhappy about what we witnessed this morning and we will get to the bottom of it."

The president did not mention any of the recipients of the packages by name in the remarks but called upon the nation to come together, saying "in these times, we have to unify."

Trump made the comments at an event on opioid abuse.