President Donald Trump on Monday proposed tighter monitoring of the internet, mental health reform and wider use of the death penalty in response to mass shootings over the weekend that killed 31 people in Texas and Ohio.

Republican Trump, who has been criticized by Democrats as stoking racial divisions with his rhetoric, said Americans must "condemn racism, bigotry and white supremacy," a day after Texas officials said racial hatred was a possible motive in the killings of 22 people in the southern border town of El Paso.

A 21-year-old white man has been charged with capital murder in Saturday's shooting spree. Police in El Paso cited a racist, anti-immigrant manifesto posted online shortly before the shooting, which they attributed to the suspect, Patrick Crusius.