The Washington Post reported that US Secretary of State Condoleezza Rice will offer support for ElBaradei's candidacy as director-general of the Vienna-based International Atomic Energy Agency (IAEA).
But Rice will make it clear that the US expects some things in return, the newspaper said on Wednesday, citing two US officials.
"We're willing to lift our objections under certain conditions," one of the officials was quoted as saying.
"Namely, get tougher on Iran."
ElBaradei has headed the IAEA since 1997. He fell out with Washington over what they saw as soft-pedalling on the atomic programmes of Iraq and Iran.
ElBaradei was due to arrive in Washington late on Wednesday. He was scheduled to meet Rice and Undersecretary of State for Arms Control Robert Joseph on Thursday, the newspaper said.
"We're willing to lift our objections under certain conditions"
Unnamed US official
Investigation on Iran
The IAEA has been investigating Iran's nuclear programme for over two years but has found no hard proof that Tehran is developing nuclear weapons as Washington insists.
However, it has found many potentially weapons-related activities that Iran concealed from the United Nations for nearly two decades.
Iran says its nuclear programme is for electricity generation, but ElBaradei has said the "jury is still out" on whether Iran has a weapons programme.