Sanders told reporters about the timeline during her daily press briefing. Her comments came hours after Trump said he planned to make the announcement "over the weekend," potentially as early as Friday afternoon.
"We'll issue it sometime over the weekend; sometime today or over the weekend, we'll have a decision," Trump told reporters. "We'll issue it sometime over the weekend, maybe this afternoon."
When asked by a reporter if "dreamers" -- the young people allowed to stay in the country under the Deferred Action for Childhood Arrivals program -- should be worried, Trump said "we love dreamers."
"We love everybody. ... We think the dreamers are terrific."
Earlier in the day, House Speaker Paul Ryan urged Trump to hold off on potentially ending the policy, saying it's something "Congress has to fix."
Ryan's comments to a Wisconsin radio show come as business leaders and immigration rights advocates lobby the Trump administration not to repeal the policy of deferring deportation for immigrants brought to the United States as children.
"I actually don't think he should [repeal it] and I believe this is something Congress has to fix," Ryan said.
The push comes ahead of a Tuesday deadline by a group of 10 states that are threatening to sue the federal government if the program is not ended.
If Trump opted to end DACA, the decision would fulfill a campaign promise -- but during his inaugural address, Trump softened his rhetoric toward affected immigrants, referred to as "dreamers."
In the address, Trump promised the government would treat childhood immigrants with "great heart."
Many of those covered by DACA have no recollection or ties to their native country after growing up in the United States.
In the meantime, a group of immigration rights advocates continue to hold a round-the-clock vigil in front of the White House after more than two weeks, urging Trump to allow an estimated 800,000 young immigrants covered by DACA to remain in the country.
A group of more than 100 CEOs and other business leaders also submitted an open letter calling on Trump and Congress to pass legislation granting those young immigrants a path to citizenship, noting the economic benefits they provide.
"Unless we act now to preserve the DACA program, all 780,000 hardworking young people will lose their ability to work legally in this country, and every one of them will be at immediate risk of deportation. Our economy would lose $460.3 billion from the national GDP and $24.6 billion in Social Security and Medicare tax contributions," the letter states.
The appeal was signed by some of the nation's most prominent CEOs from across the business landscape -- including Mark Zuckerberg of Facebook, Satya Nadella of Microsoft, Reed Hastings of Netflix, Mary Barra of General Motors, Alfred F. Kelly Jr. of Visa and Meg Whittman of Hewlitt Packard.