U.S. presidential nominee, Democrat Barack Obama, says his rival's health care plan is "radical" and could cause millions of Americans to lose their benefits.

Obama told a rally Saturday in the eastern state of Virginia that Republican presidential nominee John McCain will tax health care benefits.  He also says the McCain plan will force many companies to stop offering health care to their employees.

Obama says his plan will offer Americans more choices and more protection.

Republican Party officials say Obama is lying.

McCain is in the Western state of Arizona and is scheduled to give a media interview Saturday.

With just one month to go before the U.S. presidential election, senior aides say the Republican candidate is also changing his campaign strategy.

They say McCain plans to focus more on his opponent's character and liberal political views.

A television advertisement that began airing Friday charges Obama has not been truthful about his tax policies.

Both presidential candidates had been focused on the financial crisis. Lawmakers passed a $700 billion bailout plan for the troubled U.S. financial industry this past week and President George Bush signed it into law Friday.

Obama and McCain also are preparing for the second of their three debates, Tuesday in Nashville, in the southern state of Tennessee.

Some information for this report was provided by AFP and AP.