US President-elect Barack Obama, who has vowed to adopt an aggressive approach to global warming and the environment, was scheduled to announce his choices to lead the effort at a news conference yesterday.

Obama would hold a news conference at 5 pm EST (6 am Beijing time today) to talk about "the nation's energy and environmental future", his transition office said on Sunday.

He is expected to name Nobel physics laureate Steven Chu as energy secretary and former Environmental Protection Agency chief Carol Browner to head a new council to coordinate White House energy, climate and environment policies, Democratic sources have said.