Turkey has become a principal financial hub for terrorists under the leadership of Prime Minister Recep Tayyip Erdogan, whose government has helped Iran skirt sanctions, supported jihadi groups in Syria, and provided financial backing to Hamas, according to a new report by the Foundation for Defense of Democracies (FDD).

Turkey, a key U.S. ally, "has turned a blind eye" to terror financing and is potentially on the verge of crossing the line to becoming an official state sponsor of terrorism, according to the Friday report, which cites the Erdogan government’s close ties to some of the world’s top terror organizations and operatives.

The report comes just a day after 84 U.S. lawmakers and former government officials urged President Barack Obama to confront Erdogan over his harsh repression of political opponents.

As Turkey’s support for terrorism expands, the Obama administration has remained silent out of fear of offending Erdogan, whom the White House considers a strategic asset, according to the report authored by FDD’s Jonathan Schanzer, a former terrorism finance analyst at the U.S. Treasury Department.

The Obama administration "has remained on the sidelines, expressing relatively mild concern about the crackdowns on law enforcement officials and the jailing of journalists, while electing not to mention terrorism finance issues publicly," the report states.

"Washington’s silence stems from fears of a fall-out with Turkey, which has been a crucial ally over the years, and is situated strategically at the intersection of Europe and the Middle East," according to the report. "But Turkey’s actions constitute a direct challenge to Washington’s sanctions regime."

The report catalogues in detail Turkey’s cozy relationship with jihadi groups, terrorist operatives, and the Iranian regime.

Last year, "Turkey was involved in a massive sanctions-busting scheme with Tehran," according to the report. "Now known as ‘gas-for-gold,’ the scheme helped the Iranian regime gain some $13 billion" despite international sanctions meant to stop such deals.

Additionally, over 2,000 Iranian companies are reportedly registered in Turkey, where pro-Erdogan political elites have been accused of facilitating large cash transfers with Tehran.

Turkey’s top intelligence agency is also believed to be working with Iran in a bid to "scuttle intelligence operations" aimed at stopping Iran’s nuke program, according to the report.

Erdogan has also gone to great lengths to bolster extremist rebel groups in Syria, according to the report, which cites "mounting evidence suggests that Turkey has been directly or indirectly arming, training, and even financing Sunni jihadi groups" in the country.

Turkey reportedly sent 47 tons of weapons to Syrian rebels during a six-month period in 2013, according to the report.

There are "few questions that it has been Turkish policy to provide support to a range of rebel factions," the report states. "Turkey now appears to allow a broad spectrum of anti-Assad forces, including those with radical ideologies, to operate on Turkish territory."

"Jihadi personnel and finances" have been identified as flowing from Turkey to Syria.

Israeli military officials have additionally claimed that "Syrian al Qaeda groups were training in three separate bases in the Turkish provinces."

Erdogan has also been exposed for having a close friendship with Yasin al-Qadi, a Saudi Arabian businessman who has faced sanctions for his financial ties to al Qaeda, Osama bin Laden, and other terrorist fronts.

Hamas has become another ally of the Erdogan government, which has held meetings with the terror group’s senior leadership and allows one of its key operative to work in Turkey.

Senior Hamas leader Saleh al-Aruri has been living in Turkey, "where he has been allegedly involved in the financing and logistics of Hamas operations," according to the report, which states that "al-Aruri may be raising funds on Turkish soil that go to support terrorism."

This coincides with "broader Turkish support" for Hamas, including political cover and financial backing.

Turkey has even inked a $4 billion deal with a Chinese missile firm that has been sanctioned "multiple times by the U.S. for selling prohibited missile technology to Iran," according to the report.

Turkey’s deal with the controversial China Precision Machinery Import and Export Corp appears "to be a direct attempt to undermine the U.S.-led sanctions against Iran," the report states.

The Turkish government’s growing ties to terror have come amid a corruption scandal that has rocked Erdogan’s AKP political party, which has "purged the investigators, prosecutors, and journalists involved" in exposing the corruption.

FDD’s Schanzer warned that left unchecked by the United States and the rest of the international community, "Turkey’s terrorism finance problems could fester further."

"These problems have already raised questions about whether Turkey currently serves as a barrier to extremism from the Middle East," Schanzer said.