President Obama on Wednesday criticized the escalating violence in Ukraine and warned Kiev's government of tough consequences if the crackdown on protesters continues.

"The United States condemns in the strongest terms the violence that’s taking place. And we have been deeply engaged with our European partners as well as the Ukrainian government and the opposition to try to ensure that that violence ends,” said Obama in Toluca, Mexico, where he is attending the North American Leaders Summit.

“We hold the Ukrainian government primarily responsible,” the president said, adding that the U.S. would “be watching closely and we expect the Ukrainian government to show restraint, to not resort to violence in dealing with peaceful protesters.”

“We’ve also said we expect peaceful protesters to remain peaceful and we’ll be monitoring very closely the situation, recognizing that with our European partners and the international community there will be consequences if people step over the line,” he cautioned.

Violence in Kiev erupted on Tuesday after security forces backing Ukrainian President Yiktor Yanukovych’s government attacked protesters massed in Independence Square. The clashes left at least 25 dead.

Opposition groups are pushing for closer ties with the European Union and reforms they say will further democratize Ukraine. Yanukovych blocked an EU trade deal in favor of closer ties with Russia.

Earlier Tuesday, deputy national security adviser Ben Rhodes said that the administration had an array of options, including sanctions, they would use to force Kiev back to the negotiating table.

“We have made it clear we would consider taking action against individuals who are responsible for acts of violence within Ukraine,” Rhodes added. “We have a toolkit for doing that that includes sanctions.”

Vice President Joe Biden on Tuesday also called Yanukovych to express his “grave concern” over the violence and urged the Ukrainian leader to hold meaningful talks with opposition groups.

But both sides show no signs of pulling back in the standoff, with security forces vowing to intensify their crackdown if the protesters do not disperse.

Obama on Wednesday said that whatever path Ukraine took, it should be decided by the people and not the country’s military.

“The United States will continue to engage with all sides in the dispute in Ukraine and ultimately our interest is to make sure the Ukrainian people can express their own desires,” said the president.

“We believe a large majority of Ukrainians are interested in an integration with Europe,” he added. “But regardless of how the Ukrainian people determine their own future, it is important the people themselves make those decisions and that’s what the United States will continue to strive to achieve"