President George Bush has formally endorsed Republican Senator John McCain, who secured the party nomination for 2009 presidential election, winning all four primary contests on Tuesday.
The 71-year-old Arizona Senator won the Republican presidential nomination, eight years after he lost it to President Bush.
Earlier, President Bush, invited McCain to the White House for a warm endorsement.
"John showed incredible courage and strength of character and perseverance in order to get to this moment and that is exactly what we need in a President," he said.
Despite his low approval rating, Bush is very popular among conservative Republicans, whose support McCain needs to win the general election. Bush can also help in fund raising.
McCain is a veteran pilot during the Vietnam War. He was shot down during a bombing mission and was a prisoner of war in Vietnam for five-and-a-half years. If successful, he would be the oldest American ever elected to a first term as President.
Image: President Bush and John McCain wave to cameras at the Rose Garden of the White House.
Reportage: UNI | Photograph: Alex Wong/Getty Images