Washington: The rise of new economic powers like India, China and Brazil should not be at the cost of the United States' opportunities and influence in the world, a top American Senator has said.

"Globalisation, the spectacular economic growth of China India, Brazil and others, China's growing political and military assertiveness, competition for energy resources, the financial crisis of 2008 and the deep recession and weak recovery that followed, our mounting national debt...are often cited among other reasons as contributing factors in America's diminished capacity for world leadership," Senator John McCain said.

"But for all our problems, we still stand the best chance of not just surviving global changes but using them to advance our progress and strengthen our position in the world. The rise of new economic powers – China, India, Brazil and others – doesn't have to come at the cost of our opportunities and influence in the world," McCain said in his address at the US Naval Academy in Annapolis, Maryland.

He, however said, for all the challenges the US faces, and for all the changes occurring in the world, he is "convinced that America still has the greatest capacity to lead the world; that most of the world wants US to lead; and that it is necessary, for its future and the future of humanity, that America leads".

He said he had spoken with many people risking their lives to bring an end to autocracy and institute government by the consent of the governed in the various movements that comprise the Arab Spring.

"Their message is always the same. Yes, we want America's help, but not just when it's safe, but when we need it most, as the old regimes fight desperately to hang on to power.

"They want to know that we act not only in our self-interest, but in solidarity with the cause of human freedom wherever it is threatened. That's why I am so concerned that US is failing to exercise leadership in Syria," McCain said.