A Ku Klux Klan newspaper has declared support for Donald Trump's Republican run for U.S. president, saying America became great because it was a white, Christian republic.

The Crusader, one of the white supremacist group's most prominent publications, published a lengthy endorsement and defense of Trump's message on the front page of its current issue under the headline: "Make America Great Again."

"Make America Great Again" is Trump's campaign slogan.

The Trump campaign rejected the group's support. In a statement, campaign spokesman Steven Cheung said, "Mr. Trump and the campaign denounces hate in any form. This publication is repulsive and their views do not represent the tens of millions of Americans who are uniting behind our campaign."

The KKK is the oldest white supremacist group in the United States, tracing its roots back to the Reconstruction period in the South that followed the Civil War. In addition to anti-black views, it has expressed anti-Semitic, anti-immigrant and anti-gay views and, until recently, was anti-Roman Catholic.

There has been a rise in Islamophobic attacks and anti-refugee tendencies in United States in recent years, including the Republican presidential candidate Donald Trump calling for a ban on Muslims and migrants.

In addition, there have been clashes in U.S. cities due to police brutality against the black citizens, signaling racial tensions and discrimination against people of color and other minority communities.