WASHINGTON (CNN) -- Sen. Sam Brownback will end his bid for the presidential nomination on Friday, two sources tell CNN.
The announcement will be made in Brownback's home state of Kansas, a source said.
A campaign source tells CNN "all scheduling put on hold pending a major announcement."
A source said Brownback had no immediate plans to endorse one of the remaining Republican candidates in the race, but he has noted before that he would support his party's nominee.
Brownback, a social conservative, was never able to break into the top tier of Republican candidates. In the latest CNN/Opinion Research Corporation poll conducted October 12-14, Brownback as the top choice of 1 percent of the registered Republicans polled.
The poll's margin of error was plus or minus 5 percent.
Brownback also had difficulty fundraising. On Monday, Brownback reported raising about $926,000 for his presidential campaign in the third quarter. Watch rival say what Brownback's move means for him »
A source tells CNN that he has less than $100,000 in the bank and has little prospect to improve his fundraising due to his low poll numbers.
When the report came out, Brownback gave no indication Monday he would abandon his White House bid despite the lackluster haul. Instead, the Brownback campaign noted that the Kansas senator is eligible to receive "at least $2.1 million in federal matching funds," and emphasized that the campaign is carrying no debt.
"With a crowded field and an entire month during which Senator Brownback campaigned in Iowa without holding fundraising events, we are pleased with the level of support for Senator Brownback's message," John Rankin, the senator's campaign spokesman, said in a statement.
"We have always expected to run a grassroots campaign and to make the most of limited resources. The option of over $2 million in federal matching funds would provide additional support as we move forward."
Several of Brownback's opponents for the GOP presidential nomination had a much more successful three-month fundraising period. Former New York City Mayor Rudy Giuliani raised $11 million, while former Massachusetts Gov. Mitt Romney collected $10 million. Texas Rep. Ron Paul's success in the third quarter was the biggest surprise when he announced raising $5 million for his bid. E-mail to a friend
CNN's John King and Mark Preston contributed to this report.