President Obama on Monday hailed the Supreme Court decision to strike down several provisions of the controversial Arizona immigration law but expressed concern about implementation of the remaining provision.

“I am pleased that the Supreme Court has struck down key provisions of Arizona's immigration law,” Obama said in a statement released by the White House. “At the same time, I remain concerned about the practical impact of the remaining provision of the Arizona law that requires local law enforcement officials to check the immigration status of anyone they even suspect to be here illegally.”

The Supreme Court tossed out three of four contested provisions of Arizona’s controversial immigration law in a ruling handed down Monday morning. The remaining portion allows law enforcement officials in the state to demand a person show proof of citizenship if they suspect he or she might be in the country illegally when stopped on suspicion of committing a separate offense. Critics have said the provision allows for racial discrimination.

“I agree with the Court that individuals cannot be detained solely to verify their immigration status. No American should ever live under a cloud of suspicion just because of what they look like,” he said. “We can solve these challenges not in spite of our most cherished values — but because of them. What makes us American is not a question of what we look like or what our names are. What makes us American is our shared belief in the enduring promise of this country — and our shared responsibility to leave it more generous and more hopeful than we found it.”

Obama, in his statement, urged lawmakers to act on immigration reform and promised to “work with anyone in Congress who’s willing to make progress on comprehensive immigration reform that addresses our economic needs and security needs, and upholds our tradition as a nation of laws and a nation of immigrants.” 

Republican presidential candidate Mitt Romney and the Republican National Committee each issued statements blaming Obama for a “failure to lead” on the issue.

“What this decision makes unmistakably clear is that Congress must act on comprehensive immigration reform,” Obama said.  “A patchwork of state laws is not a solution to our broken immigration system — it’s part of the problem.”

The Obama administration protested the Arizona law when it was passed in 2010 and sued the state, successfully preventing Arizona from implementing the legislation.

Arizona Gov. Jan Brewer (R) welcomed the Supreme Court’s decision on Monday, saying she is “grateful” her state can finally implement the remaining provision in the bill and promising to do so.

Obama’s statement also offered a word of caution to Brewer in her endeavor. 

“Going forward, we must ensure that Arizona law enforcement officials do not enforce this law in a manner that undermines the civil rights of Americans, as the Court’s decision recognizes,” he said. 

Obama earlier this month announced that his administration would stop deporting illegal immigrants who came to the United States before they were 16, are younger than 30, have lived here for five years, have no criminal history, and graduated from a U.S. high school or served in the military. 

He referred to that decision in his statement, emphasizing the need to enforce immigration laws “by focusing on our most important priorities like border security and criminals who endanger our communities, and not, for example, students who earn their education.”