Several US national monuments could be reduced in size or changed under proposals submitted to Donald Trump.

A leaked report written by US interior secretary Ryan Zinke recommends that six of the 27 sites should be cut in size and changes made to around four others.

The areas facing a reduction - Utah's Bears Ears and Grand Staircase-Escalante, Nevada's Gold Butte, Oregon's Cascade-Siskiyou and two marine national monuments, the Pacific Remote Islands and Rose Atoll, were all designated over the last two decades.

Image: The Mojave Trails national monument in California

A four-month review was ordered by Mr Trump earlier this year after he complained the monuments were "land grabs" by former presidents, including Barack Obama.

The report, which the White House has refused to release since it was presented in August, will spark fears among Mr Trump's opponents that reclaimed land might be offered for mining or other business interests.


And significant reductions in the size of the monuments, especially those created by Mr Obama, will be seen as another example of Mr Trump seeking to overturn his Democratic predecessor's legacy.

Image: The view from Comb Ridge, also in Utah's Bears Ears area

National monuments are areas of natural beauty and historical significance preserved for future generations.

They are not as protected as US national parks, but some have limits on mining, timber cutting and recreational activities such as off-road vehicles.

Conservationists are vowing to oppose any attempts to reduce the size of monuments or rescind their designations.

Image: Protests have been held in Utah, where two national monuments are being reviewed

Jamie Williams, president of the Wilderness Society, said the recommendations apparently made by Mr Zinke "represent an unprecedented assault on our parks and public lands" by the Trump administration.

"This callous proposal will needlessly punish local, predominantly rural communities that depend on parks and public lands for outdoor recreation, sustainable jobs and economic growth," Mr Williams said in a statement.

"We believe the Trump administration has no legal authority to alter or erase protections for national treasures. If President Trump acts in support of these recommendations, The Wilderness Society will move swiftly to challenge those actions in court."