WASHINGTON: President Barack Obama on Monday nominated two Cabinet officials who are expected to focus on tackling climate change, one of the priorities in his second term of office.

A longtime environment official, Gina McCarthy, was named to head the Environment Protection Agency and scientist Ernest Moniz was selected for the Energy Department.

Obama also tapped Wal-Mart's Sylvia Mathews Burwell to be his next budget chief, thrusting her into the center of Washington's heated partisan financial battles.

The nominations signal the White House's desire to get back to normal business after the president and Congress failed to avert the $85 billion in automatic spending cuts that started taking effect Friday. While the president has warned of dire consequences for the economy as a result of the cuts, the White House does not want the standoff with Congress to keep Obama from focusing on other second term priorities, including making nominations for top jobs and pursuing stricter gun laws and an overhaul of the nation's immigration system.

Speaking of McCarthy and Moniz at a White House ceremony, Obama said: "They're going to be making sure we're investing in American energy, that we're doing everything to combat the threat of climate change, that we're going to be creating jobs and economic opportunity. They are going to be a great team."

McCarthy is a 25-year veteran of environment policy and politics and is known for a matter-of-fact approach appreciated by both businesses and environment advocacy groups.

Among her past bosses: Obama's Republican presidential opponent Mitt Romney, for whom she was a special adviser on climate and environmental issues.

Since coming to Washington in 2009, McCarthy has been the most prominent defender of EPA policies. As the head of the air pollution division, she has been behind many of the agency's most controversial new rules - from placing the first limits on greenhouse gases on newly built power plants to the first-ever standard for toxic mercury pollution from burning coal for electricity.

Moniz, 68, oversees Massachusetts Institute of Technology's Energy Initiative, a research group that focuses on innovative ways to produce power while curbing greenhouse gas emissions. But unlike outgoing Energy Secretary Steven Chu, he is also well-versed in the ways of Washington, having served as the Energy Department's undersecretary in the Clinton administration.

Moniz has also advised Obama on central components of the administration's energy plan, including a retooling of the country's stalled nuclear waste program, energy research and development, and unconventional gas.

In a 2009 interview, Moniz noted that he learned to balance both political and scientific demands while working in the Clinton administration. "Physics sometimes looked easy compared to doing the people's business," he said.

Speaking of his budget chief, Obama said Burwell not only knows how "to make the numbers add up" but also to ignite middle class economic growth. He said Burwell and her team would face particular challenges as the budget cuts take hold, but said he was confident they would "do everything in their power to blunt the impact of these cuts on businesses and middle class families."

Burwell is Washington veteran, having served in several posts during the Clinton administration, including deputy budget director. She currently heads the Wal-Mart Foundation, the philanthropic arm of the retail giant, and previously served as president of the Gates Foundation's Global Development Program.

All three nominees announced Monday must be confirmed by the Senate.