President Donald Trump has condemned "racism, hatred and white supremacy" in an address following mass shootings that left 29 dead in Texas and Ohio.
He called for mental health gun control reforms, the death penalty for those who commit mass murder and more bi-partisan co-operation over gun laws.
"Mental health and hate pull the trigger, not the gun," Mr Trump said, speaking at the White House on Monday.
He did not express support for gun control measures proposed in Congress.
"In one voice, our nation must condemn racism, bigotry and white supremacy," Mr Trump said on Monday. "These sinister ideologies must be defeated. Hate has no place in America."
His comments came shortly before the suspect in the El Paso, Texas, shooting was charged with capital murder.
The president outlined a number of policies, including more co-operation between agencies and social media companies, mental health laws, and changes to the culture of glorification of violence.
He called for red flag laws that would allow law enforcement authorities to take away weapons from individuals believed to be a threat to themselves or others.
Mr Trump said government agencies must work together and identify individuals who may commit violent acts, prevent their access to firearms and also suggested involuntary confinement as a way to stop potential attackers.
He also said he directed the justice department to propose legislation to ensure those who commit hate crimes and mass murders face the death penalty.
The president had earlier tweeted that lawmakers in Congress should pass background check legislation in a package with "desperately needed immigration reform".
He did not reference background check policies in his address.
Mr Trump went on to say that he is "open and ready to discuss all ideas that will actually work" and said Republicans and Democrats should "join together in a bi-partisan fashion to address this plague".
"It is not up to mentally ill monsters, it is up to us."
Democrats in the House of Representatives earlier this year passed a bill that would mandate new background checks for gun transfers.
The Republican-controlled Senate has not yet taken up the legislation.
Senate Democratic leader Chuck Schumer has called for the chamber to end its summer recess in order to vote on the background checks bill.
Republican leader Mitch McConnell has not responded to the demands from Democrats.
What happened in El Paso?
The gunman opened fire on a crowded Walmart on Saturday with a semi-automatic rifle, and surrendered after being confronted by police officers outside the store.
The mass shooting, believed to be the eighth deadliest in modern US history, took place in a city where most of the population of 680,000 is of Hispanic descent.
In addition to the 20 fatalities, 26 people were injured.
The Walmart, near the Cielo Vista Mall, was full of shoppers buying back-to-school supplies at the time of the shooting, and witnesses described scenes of chaos as customers fled for their lives.
Security camera images of the attacker show an armed man in a dark T-shirt wearing glasses and what appear to be ear protectors.
The victims have not yet been named by police, but Mexico's President Andrés Manuel López Obrador said six Mexican nationals were among the dead and seven others were injured.
The suspect has been named by US media as Patrick Crusius, a resident of the city of Allen, in the Dallas area, about 650 miles (1,046km) east of El Paso.
He has been charged with capital murder, meaning he could face the death penalty.
He is believed to be the author of a text posted on 8chan, an online message board frequently used by the far right, which says "this attack is a response to the Hispanic invasion of Texas" and talks about "cultural and ethnic replacement brought on by invasion".
The four-page document, reportedly posted some 20 minutes before police received the first emergency call from the Walmart, also expresses support for the gunman who killed 51 people in Christchurch, New Zealand, in March.
US cyber security firm Cloudflare said it would terminate 8chan as a customer following the attack.
"The rationale is simple: they have proven themselves to be lawless and that lawlessness has caused multiple tragic deaths," Cloudflare chief executive officer Matthew Prince wrote in a blog post .
Mexican Foreign Minister Marcelo Ebrard said the attorney general was considering litigation claiming that terrorism was committed against Mexicans in the shooting.
What happened in Dayton?
A gunman killed his sister and eight others in an attack that lasted only 30 seconds at a popular nightlife district in the early hours of Sunday morning.
Security camera footage shows dozens of people racing through the doorway of the local Ned Peppers nightclub.
Seconds later, the gunman - identified as Connor Betts, 24 - is seen running towards the venue and being hit by police gunfire as he reaches the door.
Police said he had worn body armour and came carrying extra ammunition for his semi-automatic rifle with high-capacity magazines.
"Had this individual made it through the doorway of Ned Peppers with that level of weaponry, there would have been catastrophic injury and loss of life," said Dayton Police Chief Richard Biehl.
Officials said it was too early to speculate about motives for the attack.
But responding to questions about a possible racial element to the killings, Mr Biehl said there was nothing to suggest a "bias motive".
Police say the rifle was ordered online from Texas and there was nothing in the gunman's history that would have stopped him from buying the gun legally.
Since the shooting, a number of the gunman's former classmates have came forward to say he was expelled from high school for having a "hit list" of people he allegedly wanted to kill .
His sister Megan was among the dead. Police listed all nine of the victims:
- Lois Oglesby, 27
- Megan Betts, 22
- Saeed Saleh, 38
- Derrick Fudge, 57
- Logan Turner, 30
- Nicholas Cumer, 25
- Thomas McNichols, 25
- Beatrice Warren Curtis, 36
- Monica Brickhouse, 39
Twenty-seven others were injured in the attack.