Iran has condemned Bahrain's decision to establish full diplomatic relations with Israel.
The White House announced Bahrain's deal on September 11, four weeks after the United Arab Emirates reached a similar agreement with Israel. The three nations plan to take part in a ceremony in Washington next week.
"It was a shameful and vile decision that will go down in history as a scandalous act," the Iranian Foreign Ministry said in a press statement on September 12.
The ministry accused Bahrain of sacrificing the long-suffering Palestinians for the sake of U.S. President Donald Trump's reelection campaign.
"The Palestinian people and the Islamic world will never accept a normalization of relations with Israel," the ministry said.
Iran's Islamic Revolutionary Guards Corps (IRGC) said that Bahrain would face "harsh revenge" from its own people and the Palestinians over the Persian Gulf Arab state's move to normalise ties with Israel.
"The executioner ruler of Bahrain should await the harsh revenge of the Mujahideen [Islamic fighters] aiming to liberate [Jerusalem] and the proud Muslim nation of this country," the IRGC said in a statement published by Iranian media.
Last month, the United Arab Emirates and Israel agreed to normalize their ties amid speculation that Bahrain could follow suit.
Trump has helped broker both agreements as part of a diplomatic push to fully integrate the Jewish state into the Middle East.
Bahrain has agreed to formalize the deal with Israel at a ceremony on September 15 at the White House, where the United Arab Emirates will also sign off on its own thaw with Israel.