US SEN. ELIZABETH WARREN on Monday called Republican presidential contender Donald Trump a “blowhard” for his recent comments about U.S. Sen. John McCain and decried the partisan politics that she said are driving discussions around the new accord with Iran.

After a roundtable discussion about an employee rights bill in Boston, the Cambridge Democrat also questioned Republican reactions to prior Trump statements and voiced skepticism about the idea of arming soldiers at recruiting centers after four marines and a Navy officer were killed in a shooting rampage last week in Chattanooga, Tenn.

“The idea that we are going to reduce violence in this country by arming more and more and more people has been proven to be wrong. It’s not the right direction for us to go,” Warren told reporters.

Trump, a real estate tycoon whose rhetoric has earned him an early following in the Republican primary, dismissed the military record of his party’s 2008 presidential nominee over the weekend.

The record of McCain, an Arizona Republican, includes a bombing mission over Hanoi, Vietnam, in 1967 when his jet was shot down, resulting in him spending five years as a prisoner of war. In remarks made in Iowa on Saturday that were widely denounced by other Republican presidential candidates, Trump, who has been feuding with McCain, appeared critical of the fact that McCain was captured during his military service.

Warren, who for several months fended off calls to step into the presidential ring herself, contrasted Republicans’ denunciation of Trump Saturday with the more subdued response that followed Trump’s remarks that Mexico is sending rapists and other criminals into America.

“Donald Trump calling John McCain anything other than a hero is just Donald Trump being a blowhard,” Warren said. “But I noticed that the other Republican presidential candidates immediately jumped on him for that, and good for them. But where were they when Donald Trump shot off his mouth about Mexican Americans? Where was he then? The answer was they hid in the shadows.”

The New York Times on Sunday and Monday reported on murder and other wrongdoing occurring in international waters where the newspaper said “egregious crimes are routinely committed with impunity.” Asked about the situation, Warren said all countries that depend on trade through international waters have a “responsibility” to try to make the seas safer.

“This is not only a bad problem, but it’s a bad problem that’s gotten worse,” Warren said. She said, “The United States has not been a full participant in the treaties about the high seas, and I think it’s important that that’s a first step, but we need to work with our allies around the world to squeeze out this kind of lawlessness.”

The US agreement with Iran to lift sanctions on the country in exchange for inspection of its purportedly non-weaponry nuclear development will spark disagreement along party lines, said Warren, who challenged opponents to put forward their own ideas.

“It really is a sad statement that the first thing we do when we reach this historic accord is turn to partisan politics in Washington,” Warren said. She added, “If others have an alternative path that they want to spell out, a military solution, then they need to put it on the table, and people around this country need to be able to evaluate that.”

Critics have said the agreement will allow Iran to continue supporting paramilitary and terrorist organizations around the region and would only offer a modest delay to the nation’s ability to develop a nuclear weapon.

After the deal was announced last week, Warren said she needed to review the details but praised the use of diplomacy and the success of the US negotiators, including Secretary of State John Kerry, in reaching an agreement.

After what she said were several briefings and texts on the deal since then, Warren on Monday said the deal “moves us strongly” away from an Iran with a nuclear weapon.

“A nuclear Iran is completely unacceptable. It is a danger to the region. It is a danger to the United States. It is a danger to the world,” Warren said. She said, “A negotiated solution is our best chance to hold Iran to no nuclear weapons.”

Asked if she was willing to put her full support behind Democratic presidential frontrunner former US Secretary of State Hillary Clinton, Warren said she is keeping an open mind on the Democratic field – which includes US Sen. Bernie Sanders of Vermont; former Maryland Gov. Martin O’Malley; former US Sen. Jim Webb of Virginia; and former US Sen. Lincoln Chafee of Rhode Island.

“I am right now listening to the candidates lay out their issues and what they want to run on,” Warren said.

When the same reporter who asked about Clinton – Sharman Sacchetti, of Fox-25 – tried to ask Warren a question about the Olympics, the senator asked whether any reporters who had not previously asked a question had any queries.

Answering her final press question before leaving the event, Warren said she would “very much like to see Cuba as soon as I can.”