As Congress embarks on a two-month review of the nuclear agreement with Iran, opponents of the deal are pouring millions of dollars into a massive ad campaign airing in Hawaii and dozens of other states across the country.

The effort to pressure wary lawmakers into rejecting the deal is paid for by a new group called Citizens for a Nuclear Free Iran, which is backed by the powerful American Israel Public Affairs Committee.

So far, the group has paid a total of about $76,000 to four Honolulu TV stations to run the ads arguing that the nuclear accord negotiated between six countries and Iran will ultimately make the world less safe.

According to the Federal Communications Commission, the group paid about $29,300 to KGMB, $13,300 to KHNL, $9,600 to KHON and $24,000 to KITV for the campaign, which began July 13 and runs at least through Aug. 2.

The group’s first ad argues that, under the deal, Iran will be able to keep its nuclear sites, has long violated international agreements and supports international terrorism.

Congress has until Sept. 17 to decide whether to approve or reject the agreement aimed at reining in Iran’s nuclear program in return for sanctions relief. Many Republicans have come out strongly against the accord, which they say will threaten Israel.

President Barack Obama, who sent Defense Secretary Ashton Carter to Jerusalem this week to pledge U.S. security assistance to Israel, has said he will veto any measure to derail the agreement, and opponents would need two-thirds majorities in the Senate and House to override the veto.

The members of Hawaii’s congressional delegation issued statements last week saying that they are eager to review the terms of the accord.

U.S. Sen. Brian Schatz said the announcement of the agreement “marks a watershed moment in our pursuit to stop the spread of nuclear weapons.”

“If this is a good deal, it is the first step in a long road to blocking Iran’s access to a nuclear weapon, and we must remain vigilant to ensure Iranian compliance,” Schatz said. “Our guiding principle must continue to be distrust but verify.”

U.S. Sen. Mazie Hirono called the accord “historic” and “comprehensive.” “The pathway to implementing a deal to effectively prevent Iran from obtaining or developing a nuclear weapon is in sight,” she said.

U.S. Rep. Tulsi Gabbard struck a more cautious tone. “We need to see a tough, verifiable inspections regime that applies anytime and anywhere, including military sites,” she said. “We cannot afford to make the same mistake with Iran that was made with North Korea. The failure to stop North Korea from developing nuclear weapons has resulted in an unacceptable threat: North Korea’s long-range missiles, coupled with its nuclear warhead stockpile, puts my home state of Hawaii and the West Coast directly in Pyongyang’s cross-hairs.”

U.S. Rep. Mark Takai was more sanguine. “I have consistently advocated for diplomatic solutions to our nation’s foreign policy objectives and appreciate the administration’s efforts to reach an agreement with Iran regarding their nuclear program,” he said. “I look forward to an open debate on the merits of this deal and hope that in the end it will meet standards that will help improve the regional security in the Middle East.”