John McCain campaining in South Dakota, 5 Jul 2008

Republican presidential candidate John McCain has a new television ad that acknowledges the United States is worse off than it was four years ago.

The ad, unveiled Tuesday, is an effort by McCain to distance himself from his own party, which has held the U.S. presidency for the past eight years.

The ad promises that McCain will reform Wall Street and battle big oil companies if elected, stressing the theme of change also used by his Democratic rival, Barack Obama.

Obama used a campaign stop in the state of Ohio Tuesday to portray McCain as more concerned about oil company profits than reforming energy policy.

Obama accused the Republican of taking a page out of the "Cheney playbook", a reference to Bush administration policies that Democrats say are biased in favor of oil companies.

McCain visited a nuclear plant in the state of Michigan Tuesday to reiterate his calls for building more nuclear power plants and expanding offshore oil drilling.

Obama said last week that, while he continues to oppose offshore drilling, he could agree to some offshore exploration as part of a bi-partisan plan to reduce energy prices.

In another development, the McCain campaign is spending $6 million on advertising during U.S. television coverage of the Beijing Olympics, which begin Friday.

Last month, the Obama campaign purchased $5 million worth of advertising for the same Olympic television coverage.

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