When the Massachusetts Democrat was asked Wednesday on ABC's "The View" if she regretted not running for president, Warren said: "Look, we all have a lot of regrets, but my biggest regret is that Donald Trump is president of the United States, period. That is where we are. That is where we are today."
Warren also said she doesn't understand when people ask her if she thinks Bernie Sanders should have dropped out of the race earlier, explaining the Democrats had a "real primary going on."
As for whether she should have thrown her weight behind Hillary Clinton sooner, Warren said she did her part.
"Once it was clear how that primary was going to be resolved, I got in and I busted my tail to try to help her get elected and I wish it had worked. God dang, I wish it had worked," the senator said.
Warren, known as a liberal firebrand, called Trump a "master of distraction," joking that his young presidency seems to have gone by in "dog years."
She also accused the president of reneging on his campaign promises to protect the interests of middle- and working-class voters. Warren said the failed GOP health-care bill was "like the whole thing in one microcosm."
She said Trump was not serving his constituents by endorsing a plan that would knock 24 million people off of their coverage to help finance a tax cut for the wealthy.
The White House did not immediately respond to a request for comment.