President Trump has said last week's attack in Portland that left two dead was 'unacceptable'.
The incident happened on Friday afternoon on one of the city's light rail trains.
According to police, a man was shouting "various remarks that would best be characterised as hate speech toward a variety of ethnicities and religions".
Oregon Live reports that he was "allegedly berating a Muslim girl in a hijab and her friend".
When a number of people attempted to intervene, the man is said to have stabbed three men.
Two of the stabbed men - named as Ricky John Best (53) and Taliesin Myrddin Namkai Meche (23) - died following the attack.
A third man - Micah David-Cole Fletcher (21) - received serious injuries in the attack, but his condition is not believed to be life threatening.
Local police have been named the suspect as Jeremy Christian (35), who was arrested shortly after the incident.
He faces charges including aggravated murder, attempted murder, and intimidation.
UPDATE #2: Two Dead, One Injured in Stabbing on MAX Train at Hollywood Transit Station -- Suspect in Custody (Phot… https://t.co/zKWAYGW5tV pic.twitter.com/iqud8ISToW
— Portland Police (@PortlandPolice) May 27, 2017
In a statement released over the weekend, Portland Mayor Ted Wheeler said: "Two men lost their lives and another was injured for doing the right thing, standing up for people they didn't know against hatred.
"Their actions were brave and selfless, and should serve as an example and inspiration to us all. They are heroes."
In a tweet from his official 'POTUS' account earlier today, President Trump said the victims "were standing up to hate and intolerance".
The violent attacks in Portland on Friday are unacceptable. The victims were standing up to hate and intolerance. Our prayers are w/ them.
— President Trump (@POTUS) May 29, 2017
Ahead of today's tweet, there had been mounting calls for President Trump to comment on and condemn the attack.
In an open letter to the US president, retired news anchor Dan Rather wrote: "I wish we would hear you say these names, or even just tweet them.
"Two Americans have died leaving family and friends behind. They are mourned by millions more who are also deeply worried about what might come next."
