The United States needs to regain its leadership role in the world, Republican Jeb Bush will say in a speech on Wednesday, while asserting that President Barack Obama has been inconsistent and indecisive in carrying out American foreign policy.

Bush's speech at the Chicago Council on Global Affairs will be his first major foray into foreign policy since he announced in December that he is considering a run for the 2016 Republican presidential nomination.

"The great irony of the Obama presidency is this: Someone who came to office promising greater engagement with the world has left America less influential in the world," Bush will say, according to speech excerpts that were provided to Reuters.