Firing the first salvo after Barack Obama sealed the Democrat presidential nomination, Republican rival John McCain on Wednesday described him as a man incapable of making "tough calls" and standing firm in the face of criticism.

Addressing an election rally in New Orleans, Louisiana, shortly before 46-year-old Obama declared victory, the presumptive Republican nominee also sought to distance himself from President George W Bush [Images] on energy, military and economic policies.

The Vietnam war veteran told a cheering crowd that they would listen a lot during the coming months that he represents third term of Bush, but that is because the Democratic candidate has nothing to offer.

Briefly introducing McCain, Indian-American Governor of Louisiana Bobby Jindal praised him as a man of principles who would not give into special interests and would stand firm in the face of criticism.

Jindal, who is very close of McCain, is on the short list of names being considered by the Republican candidate for his vice president.

Recently, McCain had invited Jindal to his house in Arizona along with some others who were being considered for that post.

Obama, McCain said, is an "impressive man" who makes a great first impression.

"But he hasn't been willing to make the tough call, to challenge his party, to risk criticism from his supporters to bring real change to Washington," he added.

McCain presented himself as the right man to bring change. "No matter who wins this election, the direction of this country is going to change dramatically. But the choice is between the right change and the wrong change, between going forward and going backward," he said.

"You know, I have a few years on my opponent, so I am surprised that a young man has bought in to so many failed ideas," McCain, 71, said.

But Obama, who addressed a victory rally about two hours later, repeated that McCain would represent the third term for Bush's failed polices which the country can ill-afford.

"While John McCain can legitimately tout moments of independence from his party in the past, such independence has not been the hallmark of his presidential campaign," he said.

"There are many words to describe John McCain's attempt to pass off his embrace of George Bush's [Images] policies as bipartisan and new. But change is not one of them," he added to laughter from the crowd.

Later, analysts discussing the two speeches noted that Obama's delivery was more spirited, which evoked much better response form the crowd than McCain's.

But McCain did try to set the agenda for the coming elections. McCain sought to fend off criticism from his opponents over Iraq, saying, "I disagreed strongly with the Bush administration's mismanagement of the war in Iraq."

With rising gas prices becoming the major campaign issue, McCain pledged to break completely with the energy policies followed by Bush and the previous Clinton administration and reduce dependence on foreign oil.

Another promise made my McCain was to cut emissions and fight global warming. If America is going to achieve energy independence, it needs a president with a record of putting the nation's interests before the special interests of either party, McCain said.

"I have that record. Senator Obama does not," he said.