President Barack Obama says "there will be consequences" for violence in Ukraine if people step over the line.
He says that includes making sure that the military doesn't step into a situation that civilians should resolve.
Obama says the US condemns the violence in the strongest terms.
He says the US holds Ukraine's government primarily responsible to ensure it's dealing with peaceful protesters appropriately.
Obama is speaking in Mexico after arriving for an international summit.
He says the US is deeply engaged with European partners, Ukraine's government and the opposition. He says the violence has captured the entire world's attention.
The US has raised the prospect of joining partners in Europe to impose sanctions against Ukraine. At least 25 people were killed yesterday in clashes between protesters and police.
