Secretary of State Rex Tillerson said Wednesday the United States will conduct a "comprehensive review" of its policy toward Iran, including the 2016 nuclear deal, which he said had merely delayed Iran's goal of becoming a nuclear state. "This deal represents the same failed approach of the past that brought us to the current imminent threat we face in North Korea," Tillerson said. "The Trump administration has no intention of passing the buck to a future administration on Iran. The evidence is clear Iran's provocative actions threaten the U.S., the region and the world." Tillerson notified Congress on Tuesday that despite finding that Iran was meeting the terms of the deal, the Trump administration was reviewing whether to break from the agreement, saying in part that Iran remains a leading state sponsor of terrorism. Wednesday, Tillerson ticked off what he called the abuses of the Islamic Republic point by point, accusing Iran of sponsoring terrorism in Syria, Iraq, Yemen and Lebanon and against Israel. Other grievances included the harassment of U.S. naval vessels, the conducting of cyber-attacks, the arbitrary detention of foreigners, including U.S. citizens, and the carrying out of ballistic missile tests in violation of U.N. resolutions. The Iran nuclear deal, which went into effect in January 2016, was an agreement among five world powers — Great Britain, France, Germany, Russia and China — and Iran. Although billions of dollars of Iran's assets were unfrozen in exchange for Iran's curbing its nuclear program, U.S. sanctions against the Islamic Republic because of its support of terrorism weren't lifted. Iran has been on the annual U.S. list of countries supporting terrorism since 1984, and as of 2015 it was determined to be the "foremost state sponsor of terrorism," above Syria and Sudan. Countries designated on the list are subject to specific U.S. sanctions, but how exactly has Iran supported terrorism around the world? According to the most recent State Department report, the Islamic Republic of Iran provides a range of support to terrorist groups, "including financial, training, and equipment." Most notably, that support is directed through the Iranian Revolutionary Guard, also known as the Quds Force (IRGC-QF), and the foreign terrorist organization, Hezbollah. Related: Trump Administration Orders Review of Iran Nuclear Deal Sanctions: Tillerson Defense Secretary James Mattis addressed those groups' impact on the region while in Saudi Arabia Wednesday. "The militia they maintain, Lebanese Hezbollah that they support in Lebanon, that militia is contributing thousands of fighters, and of course Iran's got its own military inside Syria continuing to hold [President Bashar] Assad in power," Mattis said. "Everywhere you look, if there is trouble inside the region you find Iran." Mattis was in Riyadh in part to address the crisis in Yemen, where Iranian influence and support of the Shiite Houthi rebel group against the Sunni government continues to play a major role in the nation's instability. The French, Australian and U.S. navies have all uncovered attempts by Iran to smuggle weapons to the rebel group. Iranian backing has also been crucial in propping up Assad, whose brutal crackdown has led to the deaths of more than 500,000 people and created millions of refugees. Outside of the Iran-aligned terrorist group Hezbollah, Iran has provided arms, financing and training for Iraqi, Afghan, and Pakistani Shi'ite fighters in an effort to support their ally, whom they see as crucial to maintaining their influence in the region. In Iraq, Shi'ite militias associated with the Iranian Revolutionary Guards and Kata'ib Hizballah were joined the Iraqi government's Popular Mobilization Forces fight against ISIS. But the presence of the Iranian-backed groups has exacerbated sectarian tensions and contributed to human rights abuses, primarily against Sunni civilians. For Israel, Iran is seen as an existential threat. As recently as Tuesday, a missile reading "Death to Israel" was showcased during a large military parade in Iran's capital, Tehran. The Islamic Republic has long provided weapons, training and funding to Hamas and other Palestinian terrorist groups, which have been behind a number of attacks originating in Gaza and the West Bank. The country has also provided hundreds of millions of dollars to Hezbollah in Lebanon, which has trained thousands of its fighters at camps in Iran. Since the end of the 2006 conflict, Hezbollah has carried out isolated attacks along the Lebanese border of Israel and continues to prepare for attacks against Israeli targets outside the country. Iran has also been implicated for its support of violent Shi'ite opposition attacks in the country of Bahrain. A bipartisan group of senators presented a bill in March that would impose new sanctions on Iran for sponsoring terrorism, as well as its ballistic missile tests, but it has been delayed by concerns over Iran's May presidential election. The bill, co-sponsored by Foreign Relations Chairman Bob Corker, R-Tennessee, and ranking Democrat Ben Cardin of Maryland, among others, was specifically designed to avoid undermining the 2016 nuclear deal.