WASHINGTON — A day after Secretary of State Rex Tillerson said U.S. forces would stay in Syria for the foreseeable future, Sen. Tim Kaine, D-Va., on Thursday warned that the expanded mandate outlined by the nation’s top diplomat was “unacceptable” absent a vote in Congress.

“I am deeply alarmed that yet again, the Trump administration continues to raise the risk of unnecessary war, disconnected from any firm policy objectives and core national security interests,” Kaine said in a statement.

The Virginia senator, who has tried for years to get his colleagues to debate and vote on authorizing the war against ISIS, spoke a day after Tillerson laid out plans for an open-ended U.S. deployment in Syria with goals far beyond taking out the so-called Islamic State.

In remarks at Stanford University’s Hoover Institution, Tillerson said U.S. forces would stay in the war-wracked nation to ensure ISIS does not reemerge, but also to set the stage for strongman Bashar Assad’s removal from power through political means and to contain Iranian influence.

The expanded mission drew a rebuke from Kaine, who said: “To be clear, neither the 2001 or 2002 AUMFs provide authority to target Assad or Iranian proxies in Syria, and it is unacceptable for this action to be taken absent a vote and approval of Congress.” An “AUMF” is an Authorization for Use of Military Force, an act of Congress that falls short of formally declaring war but allows presidents to send young Americans into harm’s way.

The White House has tried to hide the number of U.S. troops in Syria, leaving that information out of the public section of a legally required accounting to Congress of American forces in combat zones overseas. But the Pentagon has said there are roughly 2,000 in Syria.

“State and DoD have yet to respond to my December letter regarding reports of the changing mission for the 2,000 U.S. troops in Syria, where I noted that the actions the administration was considering far exceed the counter-ISIS mandate and lack domestic and international legal standing,” Kaine said. Yahoo News covered his concerns here.

Story continues

Senior officials, including Defense Secretary James Mattis, had alluded to the changing U.S. strategy in Syria before, but Tillerson’s remarks laid it out in greater detail.

Read more from Yahoo News: