Former U.S. President Bill Clinton made official his decision to endorse presidential candidate Barack Obama, BBC reported.

Clinton’s wife Hillary was Obama’s main rival in the race to clinch the Democratic Party’s nomination and, until the race was over, the former president was critical of Obama and his campaign on more than one occasion.

Obama and Hillary Clinton will hold their first joint rally on Friday, but Mr. Clinton won’t attend. He will be in Europe at that time.

"President Clinton is obviously committed to doing whatever he can and is asked to do to ensure Senator Obama is the next president of the United States," said spokesman Matt McKenna.

Evidently, Obama’s campaign welcomed Bill Clinton’s endorsement and said that a unified Democratic Party will be a powerful force for change.

“We’re confident President Clinton will play a big role in that," Obama’s campaign said in a statement.

Me Clinton’s move comes after a period during which the media has been constantly reporting that the relations between him and Obama are tense since the outcome of the race for the Democratic Party nomination and that they haven’t spoken to each other since then.  

Things seem to go Obama’s way while he makes efforts to eliminate the divisions within the Democratic Party and win over those who supported Mrs. Clinton in the primaries.

The Obama-Clinton joint rally will reportedly be held on Friday in the town of Unity, New Hampshire. Both candidates received 107 votes in the primary elections there.

It is not clear yet what Obama might ask Mr. Clinton to do. His campaign wasn’t specific when asked.