U.S. Democratic presidential candidate Barack Obama will return to his home state later this week with his still-unnamed vice-presidential running mate.
Obama will hold a rally Saturday in the Illinois capital of Springfield, where he kicked off his White House bid in February 2007. This rally will begin his journey to the Democratic National Convention in Denver, Colorado, where he will officially receive the party's presidential nomination.
Speculation continues to build over the identity of Obama's running mate, and when the choice will be announced. His campaign says it will announce the choice through mobile phone text messages and e-mail.
Three prominent Democrats are widely considered to be his top choices: Delaware Senator Joe Biden, Indiana Senator Evan Bayh and Virginia Governor Tim Kaine.
Obama's Republican rival, Arizona Senator John McCain, is said to be considering former Massachusetts Governor Mitt Romney, Minnesota Governor Tim Pawlenty, and Tom Ridge, a former Pennsylvania governor and the first director of U.S. Homeland Security.
McCain may announce his running mate at a rally on August 29 - his 72nd birthday and the day after Obama is to accept the Democratic nomination
The two candidates engaged in more intense criticisms on the campaign trail Tuesday. McCain criticized Obama's energy policy while visiting an oil rig platform in the Gulf of Mexico. McCain used the appearance to to highlight his support for offshore drilling.
Meanwhile, Obama lashed out at McCain for suggesting that his policy decisions are based on personal ambitions during a speech before a group of military veterans. He defended his decision to oppose the the war in Iraq and urge the U.S. to instead pursue al-Qaida in Afghanistan.
Some information for this report was provided by AFP, AP and Reuters.