US Republican presidential candidate Senator John McCain speaks during a townhall meeting in Kenner, Louisiana June 3, 2008. (Xinhua/Reuters Photo) 

Voters are nearly split on whether Obama should choose former Democratic contender Sen. Hillary Clinton as his running mate. Forty percent give a thumbs-up to the idea while 43 percent stand against it.

With new polls that showed him running ahead of his rival in three battleground states, Obama turned his attention to foreign policy issues.

Obama said because of the policies of George Bush over the last eight years, the United States continues to face grave threats, not only from terrorism, but also nuclear proliferation, climate change and poverty, genocide and disease.

"Instead of adhering to a rigid ideology, I want to get back to the pragmatic tradition of American foreign policy which has been so ably advanced by the people in this room, a policy that's focused on using all elements of American power to protect our people and to advance our interests," Obama said.

(Xinhua News Agency via Agencies June 19, 2008)