Government shutdown updates: Leavitt says Trump exploring cutting aid to Portland

President Donald Trump on Wednesday evening called on Republicans to use the first shutdown in almost 7 years to cull potential "dead wood" from within the federal government.

"Republicans must use this opportunity of Democrat forced closure to clear out dead wood, waste, and fraud," Trump said on social media, a quote later shared by official White House accounts.

"Billions of Dollars can be saved," Trump added.

White House press secretary Karoline Leavitt earlier on Wednesday told reporters that layoffs of some federal employees were "imminent."

"These are unfortunate consequences to a government shutdown," Leavitt said on Wednesday.

OMB Director Russell Vought warned Republican lawmakers on a conference call Wednesday that the Trump administration will start firing federal workers in the next "day or two," multiple sources who were on the call told ABC News.

The firings would be part of the administration’s effort to initiate a reduction in force, or RIF, targeting furloughed federal employees.

Vought issued a memo last week warning of possible cuts in the event of a shutdown.

The congressional sources on the call told ABC News Vought did not provide any additional details on which departments and agencies could be impacted, or how deep a new round of RIFs may cut into the federal workforce.

The sources said Vought also acknowledged that the WIC nutrition program -- providing funds to help feed women, infants and children -- will run out soon.

-ABC News' John Parkinson

The White House Office of Management and Budget Director Russ Vought announced that the administration is moving to cancel $8 billion in funding for programs that he claims, "fuel the Left's climate agenda."

"Nearly $8 billion in Green New Scam funding to fuel the Left's climate agenda is being cancelled," Vought said in a post announcing the move.

Vought added that more details would come from the Department of Energy.

"The projects are in the following states: CA, CO, CT, DE, HI, IL, MD, MA, MN, NH, NJ, NM, NY, OR, VT, WA," Vought added in the post.

The states that Vought listed all have at least one Democratic Senator voting against a clean continuing resolution to fund the government. The move comes after the administration paused funding for a New York infrastructure program that was championed by Senate Minority Leader Chuck Schumer.

-ABC News' Michelle Stoddart

Social Security payments to more than 74 million Americans will stay on schedule during the government shutdown, a spokesperson for the Social Security Administration tells ABC News.

"In the event of a lapse in appropriation, SSA will follow the contingency plan for continued activities, and Social Security beneficiaries would continue receiving their Social Security, Social Disability Insurance, and SSI payments," the spokesperson said Wednesday.

In a page on its website updated on Wednesday, the agency confirms there will be "no change in payment dates," adding "you will still receive your payments on time." The website also says local offices will remain open to the public but could provide "reduced services."

-ABC News' Elizabeth Schulze