Palestinian leaders accused Sudan of "betrayal" for joining the growing list of countries that have normalized relations with Israel in the past month.
Wabel Abu Youssef of the Palestinian Liberation Front, a terror group, said the normalization of ties "represents a new stab in the back of the Palestinian people and a betrayal of the just Palestinian cause."
Hamas officials were similarly indignant, reported the Jerusalem Post.
"This is a black day in the history of Sudan," a Hamas spokesman said. "The agreement jeopardizes Sudan’s future and identity and is a betrayal of the Arabs and Muslims."
The historic agreement between the Jewish state and Sudan, a country that harbored Osama Bin Laden while under a now-deposed Islamist dictatorship, required careful diplomacy from Washington.
In exchange for normalization, Secretary of State Mike Pompeo began lifting restrictions off Sudan as a show of good faith to the country's new and more liberal government.
Growing support for formal diplomatic ties with Israel has undermined the Iranian regime and radical Palestinians' efforts to promote regional instability and isolate Jerusalem.
Israel has also normalized relations with the United Arab Emirates, even permitting the sale of F-35 jets to the country.
The Trump administration is continuing to pursue normalization agreements between Israel and other Arab countries, including Saudi Arabia.
The Sudan-Israel agreement earned high praise from Congress.
"I applaud both countries for this courageous step, and the Administration for their work to broker another landmark agreement," House Homeland Security Committee ranking member Michael McCaul (R., Texas) said in a statement.
Although "national security" was one of the six themes at Thursday night's final presidential debate, moderator Kristen Welker asked no questions about the candidates' records on the Middle East.
Democratic presidential nominee Joe Biden, however, may believe in taking a different approach from President Trump. Many former Obama administration advisers criticized the Trump administration's handling of Middle East tensions in the days leading up to the current accords.