The Trump administration has suggested federal agencies may stop working with the Smithsonian Institution if its leadership does not change, ramping up a monthslong pressure campaign to align the world’s largest museum complex with its views.

In an August 28 letter to the Smithsonian’s governing body that was recently made public, administration officials said government agencies cannot “in good conscience” support the institution and may cease “loaning artifacts for exhibits, enabling procurement processes and making discretionary grants,” citing a White House report that claimed the institution was promoting “extreme political activism” at the National Museum of American History in Washington, DC.

It’s a sign that the Trump administration is considering more aggressive measures to exert influence on content at the Smithsonian, which has tried to maintain its independence despite unprecedented scrutiny of its programming. President Donald Trump has tasked aides with rooting out “woke” ideology and what he considers a rewriting of American history at the museums.

“Because these concerns arise from executive leadership and institutional ideology at the Smithsonian, the appropriate response must likewise address executive leadership and institutional ideology,” wrote Interior Secretary Doug Burgum and Vince Haley, the director of the White House’s Domestic Policy Council, in the letter.