US President Donald Trump announced big cuts to Utah's sprawling wilderness national monuments on Monday, angering tribes and environmental groups that want to keep the areas off limits to development. Trump’s announcement follows a months-long review by the Interior Department that he ordered in April to identify which of 27 monuments designated by past presidents should be rescinded or resized to provide states and local communities more control over how the land is used. Unlike national parks that can only be created by an act of Congress, national monuments can be designated unilaterally by presidents under the century-old Antiquities Act, a law meant to protect sacred sites, artifacts and historical objects. Trump has said former presidents abused the Antiquities Act by putting unnecessarily big chunks of territory off limits to drilling, mining, grazing, road traffic and other activities — a headwind to his plan to ramp up US energy output. In a speech to supporters in Utah's capital Salt Lake City, Trump called for the 1.3 million acre (0.5 million hectare) Bears Ears National Monument, created in 2016 by then-President Barack Obama, to be cut back to 228,784 acres split into two separate areas.  He also called for a 50 percent cut to the state’s 1.9 million acre Grand Staircase-Escalante National Monument created by President Bill Clinton in 1996, splitting it into three areas. Republican Congressman Rob Bishop of Utah, chair of the House Natural Resources Committee, is expected to introduce legislation after Trump's announcement to carry out the cuts, a House aide said. It is unclear if the measure would have a chance of passing the Republican-controlled body. Trump will also ask Congress to look at the areas that are being removed from the current monuments to consider designating some as a national conservation or national recreation areas, and create a co-management structure for tribes. Interior Secretary Ryan Zinke told reporters the changes were supported by Utah's Republican Governor Gary Herbert, along with Utah's congressional delegation, the state legislature, and the local county Commissioner Rebecca Bennally. But tribal leaders representing