Trump has been widely criticized for using divisive language after clashes between white supremacist groups and those opposed to them.
The US Congress passed a resolution late on Tuesday calling on President Donald Trump to condemn hate groups after Trump was criticised for his response to the violence at a white nationalist rally in Charlottesville, Virginia, a month ago.
The US House of Representatives unanimously adopted the resolution, US Representative Gerry Connolly, a Democrat from Virginia, said in a statement. The Senate approved the measure on Monday.
"Tonight, the House of Representatives spoke in one unified voice to unequivocally condemn the shameful and hate-filled acts of violence carried out by the KKK (Ku Klux Klan), white nationalists, white supremacists and neo-Nazis in Charlottesville," Connolly said.
The joint resolution, passed with the support of both Republicans and Democrats, will go to Trump for his signature.
The Congressional resolution calls on Trump to condemn hate groups and what it describes as the growing prevalence of extremists who support anti-Semitism, xenophobia and white supremacy.
It also urges Attorney General Jeff Sessions to investigate acts of violence and intimidation by white nationalists, neo-Nazis, the Ku Klux Klan and similar groups.
Trump alienated fellow Republicans, corporate leaders and US allies and rattled markets last month with comments about the violence in Charlottesville, where white nationalists and neo-Nazis clashed with anti-racism activists on August 12.
One woman, Heather Heyer, was killed and several people were wounded when a suspected white nationalist crashed his car into anti-racist demonstrators.
The Congressional resolution calls Heyer's death a "domestic terrorist attack." James Alex Fields, a 20-year-old Ohio man who authorities say drove into Heyer and other protesters has been charged with second-degree murder and other criminal counts.
On August 12, Trump denounced hatred and violence "on many sides," a comment that drew sharp criticism from across the political spectrum for not condemning white nationalists.
White nationalists had gathered in Charlottesville to protest against the planned removal of a statue of Robert E. Lee, who led the pro-slavery Confederacy's army during the US Civil War. Trump defended Confederate monuments last month.
At a rally in Phoenix on August 22, Trump accused television networks of ignoring his calls for unity in the aftermath of the violence in Charlottesville.
"I didn't say I love you because you're black, or I love you because you're white," Trump said at the rally. "I love all the people of our country."
The resolution also acknowledged the deaths of two Virginia State Police officers whose helicopter crashed as they patrolled the Charlottesville protest.