U.S. Secretary of State Rex Tillerson outlined Washington’s latest Syria strategy Wednesday, vowing to keep an open-ended American military presence beyond its stated goal of defeating the Islamic State.

Speaking at Stanford University, Tillerson articulated the clearest outline to date of the Trump administration’s Syria strategy, which prioritizes U.S. counterterror operations over the long desired removal of Syrian dictator Bashar al Assad.

Tillerson’s plan emphasized that the U.S.’s goal, first and foremost, is to prevent Syria from becoming “a platform or a safe haven” for terrorists, including the Islamic State, Al Qaeda, and their militant offshoots. This requires maintaining an indefinite American military presence in the war-torn country, a strategy which Tillerson acknowledged may be greeted skeptically by the American public.

“We understand that some Americans are skeptical of continued involvement in Syria and question the benefits of maintaining a presence in such a troubled country,” Tillerson said. “However, it is vital for the United States to remain engaged in Syria.”

Tillerson added that U.S. would not repeat the Obama administration's "mistake" of exiting Iraq.

Tillerson did not say how long U.S. troops will remain in the country or how many more will be added to the roughly 2,000 troops already there, but the announcement will no doubt fuel concerns over mission creep in the heavily fractured conflict.

Back in October, Tillerson warned that “the reign of the Assad family is coming to an end,” and on Wednesday he reiterated this stance, stating that a peaceful future for Syria requires Assad’s removal. But Tillerson also acknowledged that Assad has been bolstered by Russia and Iran, and asked for “patience” in the Geneva-led process to negotiate his removal. Notably, the secretary of state did not detail a specific timeline for Assad’s removal, but Syria analysts remain skeptical that such a day will ever come.

“Assad’s regime is corrupt, and his methods of governance and economic development have increasingly excluded certain ethnic and religious groups,” said Tillerson. “Such oppression cannot persist forever.”

The beleaguered secretary of state outlined a hefty list of to-dos in Syria. He said the U.S. would try to rein in Iran's growing influence over the country. He also briefly referenced the estimated 11 million refugees who have fled the civil war, saying that the U.S.’s end goal would be to have those Syrians and internally-displaced persons return to their homes.

Though Tillerson did not detail budget plans for U.S. humanitarian assistance, he said the U.S. would engage in “stabilization initiatives” in ISIS-liberated areas, like clearing landmines and restoring water and electricity, similar to operations underway in Iraq.

Former Secretary of State under President George W. Bush Condoleezza Rice joined Tillerson on stage for a Q&A after the speech, in which she pressed the former Exxon CEO on President Trump’s controversial use of social media.