Casting aside days of political acrimony, Israeli Prime Minister Benjamin Netanyahu on Tuesday used an address before a joint meeting of Congress to praise the work President Barack Obama has done for Israel and declared the relationship between Israel and the U.S. could never be weakened by partisanship. But Netanyahu also came down hard against a nuclear deal the U.S. is negotiating with Iran, warning that such an agreement would not block Iran's quest for nuclear weapons and would ultimately threaten the Jewish state.
Obama, who had declined to meet with Netanyahu on the Israeli leader's controversial visit to Washington, told reporters later in the day that he read a transcript of Netanyahu's speech and found "nothing new." Obama noted the Israeli leader did not offer any "viable alternatives" to preventing Iran from obtaining a nuclear weapon, and defended his administration's pursuit of a nuclear deal with Iran.
Netanyahu began his address Tuesday on a conciliatory note, apologizing for becoming yet another source of discord in Washington. His address had been arranged by House Speaker John Boehner, who extended the invitation without consulting Obama.
"I deeply regret that some perceive my being here as political. That was never my intention," Netanyahu told lawmakers. "I know that no matter on which side of the aisle you sit, you stand with Israel."
Netanyahu went on to say that the "remarkable alliance between Israel and the United States has always been above politics" and that "it must remain above politics. "
"We appreciate all that President Obama has done for Israel," he said.
RELATED: Here's who is skipping Netanyahu's speech before Congress
The Israeli leader quickly pivoted to the ongoing nuclear talks between the U.S. and Iran, an effort he warned would not prove successful.
"At a time when many hope that Iran will join the community of nations, Iran is busy gobbling up the nations," said Netanyahu. "We must all stand together to stop Iran's march of conquest, subjugation and terror."
Because the "ideology of Iran's revolutionary regime is deeply routed in militant Islam," said Netanyahu, "this regime will always be an enemy of America." He said the goals of Iran and the terrorist group ISIS are one and the same.
The problem with America's potential deal with Iran is twofold, Netanyahu said. "The first major concession," he said, is that it "would leave Iran with a vast nuclear infrastructure." Second, he continued, the restrictions imposed on Iran's nuclear program would not effectively bar violations.
"Iran has proven time and again that it cannot be trusted," said Netanyahu. "That's why this deal is so bad -- it doesn't block Iran's path to the bomb; it paves Iran's path to the bomb."
Obama, speaking with reporters in the Oval Office, disagreed with that analysis. "The bottom line is this," the president said following a debriefing from Defense Secretary Ashton Carter. "We don't yet have a deal. It may be that Iran cannot say yes to a good deal. I have repeatedly said that I would rather have no deal, than a bad deal. But if we're successful in negotiating, then in fact this will be the best deal possible to prevent Iran from getting a nuclear weapon."
RELATED: Washington reacts to Netanyahu's speech
Though Netanyahu said he sought to rise above the political fray with his speech, the reactions from lawmakers were -- as expected -- politically split. On Twitter, a number of high-profile Republicans -- including Sens. John McCain and Lindsey Graham, as well as potential 2016 contenders such as former Arkansas Gov. Mike Huckabee and former Pennsylvania Sen. Rick Santorum -- praised Netanyahu's position. Democratic House Minority Leader Nancy Pelosi, on the other hand, said Netanyahu's address had her "near tears."
"[A]s one who values the U.S.-Israel relationship, and loves Israel, I was near tears throughout the Prime Minister's speech -- saddened by the insult to the intelligence of the United States as part of the P5+1 nations, and saddened by the condescension toward our knowledge of the threat posed by Iran and our broader commitment to preventing nuclear proliferation," said Pelosi in a statement.
The manner in which Netanyahu’s speech came about turned into a source of controversy in recent weeks, creating even greater distance between the White House and Republican lawmakers, while further dividing an already fractured Congress. Nearly 50 Democratic lawmakers were absent during Tuesday’s joint meeting, protesting what they considered to be an effort by GOP leaders to undermine a potential nuclear agreement with Iran. If struck, such an agreement would serve as a cornerstone of Obama's foreign policy legacy.
Republican House Speaker John Boehner announced he had invited Netanyahu to speak before Congress a day after Obama delivered his State of the Union Address, during which the president promised to veto any new sanctions against Iran that could jeopardize the upcoming negotiations aimed at curbing the Middle Eastern country’s nuclear program.
RELATED: Activists protest as Netanyahu speaks before Congress
Additionally, the timing of Tuesday’s address has raised many an eyebrow over whether Netanyahu is politicizing the Iranian nuclear talks to shore up support ahead of the Israeli election, which is taking place March 17. Citing that election, Obama refused to meet with Netanyahu this week.
“It’s unfortunate that Speaker Boehner’s actions on the eve of a national election in Israel have made Tuesday’s event more political and less helpful for addressing the critical issue of nuclear nonproliferation and the safety of our most important ally in the Middle East,” said Massachusetts Sen. Elizabeth Warren, one of the Democratic lawmakers boycotting Tuesday's speech, in a statement to The Boston Globe.
Iranian Foreign Minister Mohammad Javad Zarif also criticized Tuesday’s speech -- though directed it toward the Israeli leader, not Boehner. When asked by a reporter Tuesday if Netanyahu’s address would impact the nuclear talks, Zarif answered: “Well he’s trying to, but I don’t think trying to create tension and conflict helps anyone.”
It's not just lawmakers who were protesting Netanyahu's speech. Dozens of demonstrators from various antiwar groups -- including Codepink, the Answer Coalition, and NK USA (Orthodox Jews Against Zionism) -- gathered Tuesday morning on Capitol Hill to protest.
Speaking on msnbc’s "Morning Joe" Tuesday, the president’s senior adviser Valerie Jarrett downplayed the controversy Netanyahu’s address has created and said that the speech had turned into a “distraction.”
“I think what’s important to keep in mind is the fundamental fact that the United States is Israel’s staunchest ally,” said Jarrett. “The president is absolutely committed to the safety and security of Israel. We share a common goal of ensuring that Iran does not develop nuclear weapons. We may disagree about the tactics of how to get there, but the important thing is that that’s our goal. And so that’s where we really keep our focus.”
Jarrett went on to say that Obama’s relationship with Netanyahu, which has always been strained, would not be weakened by whatever political factor motivated the Israeli leader’s appearance before Congress. Their relationship, said Jarrett, “can’t be undermined because this isn’t about one particular leader; this is about the country and about our commitment to the country. So the president’s not going to let anything undermine his commitment. As as long as he is president of the United States, he’s going to honor that commitment and work vigilantly to ensure Israel’s safety and security.”
Jarrett added that Obama would not be watching the speech due to his schedule. “He’s action packed,” she said.
Republicans eyeing 2016 presidential campaigns praised Netanyahu for the speech, with some throwing in additional jabs at the White House for good measure. Former Florida Gov. Jeb Bush hailed Netanayhu's "powerful message" on Twitter while Florida Sen. Marco Rubio said in a statement that the Israeli leader offered a "stark assessment of the dangerous path the administration has taken us on through its negotiations with Iran" and called for additional sanctions.
"Prime Minister Netanyahu is a Churchill in a world full of Chamberlains, and I'm disappointed with President Obama's refusal to listen," former Arkansas Gov. Mike Huckabee said in a statement.
Kentucky Sen. Rand Paul, who has sided with the administration in calling for further negotiations before resorting to new sanctions on Iran, said in a statement that he "was pleased to hear Prime Minister Netanyahu's speech to Congress today, and join him in calling for peace and standing together for our mutual interests."
Benjy Sarlin contributed to this story.