Obama spoke in the White House East Room after the high court issued its ruling on the Affordable Care Act.

In the court's 5-4 ruling, the conservative chief justice voted with four liberals in upholding the centerpiece of the law, the so-called individual mandate requiring people to have health insurance by 2014 or pay a financial penalty.

Since Congress passed the law in 2010 against Republican opposition, a national political battle has ranged over this provision, which opponents said violated the Constitution by forcing people to buy a product they may not want.

President Obama said the ruling will be the subject of intense discussion, but it is a victory for all Americans.

"I know there will be a lot of discussion today about the politics of all this - about who won and who lost," he said. "That is how these things tend to be viewed here in Washington. But that discussion completely misses the point. Whatever the politics, today's decision was a victory for people all over this country, whose lives will be more secure because of this law and the Supreme Court's decision to uphold it."

??The Supreme Court's majority opinion, written by Chief Justice John Roberts, said legal precedent demonstrates that Congress has the power to impose a tax, and this principle justifies keeping the mandate in force.

In a dissenting opinion, Justice Anthony Kennedy said he and three conservative justices believe the entire law is invalid.

Obama has faced criticism of the way he pushed the health care law through Congress, with some in his own Democratic Party saying he did not do enough to educate Americans about its benefits.

In his East Room remarks he listed those benefits and said he understands the concerns Americans expressed in what has been a "divisive" debate. But he urged Americans to leave that behind them.

"The highest court in the land has now spoken," the president said. "We will continue to implement this law. And we will work together to improve on it where we can. But what we won't do - what the country can't afford to do - is re-fight the political battles of two years ago, or go back to the way things were."