The US government will appeal after a US district court issued a temporary injunction blocking plans by the Obama administration to increase funding for human embryonic stem cell research.
The Justice Department was "likely to file this week", a spokesman said.
The court ruled in favour of researchers who say the work involves the destruction of human embryos.
President Obama lifted a ban on federal funding for stem cell research in March.
Judge Royce Lamberth said in Monday's ruling that lawsuits brought against the new guidelines could now go ahead.
But announcing its intention to appeal, the White House said on Tuesday that it was exploring "all possible avenues" to ensure that research could continue.
"I can confirm we plan to appeal," Justice Department spokeswoman Tracy Schmaller was quoted as saying by the AFP news agency.
Critics say the ban, which was kept in place by Mr Obama's predecessor, George W Bush, impeded the fight to find treatments for diseases like Alzheimer's, Parkinson's and diabetes.
The suit, which was also backed by Christian groups including the Alliance Defense Fund, is against the National Institutes of Health (NIH).
Those against the new plan to increase funding argued the NIH policy violated US law and also took funds from researchers seeking to work with adult stem cells.
"ESC (embryonic stem cell) research is clearly research in which an embryo is destroyed," Judge Lamberth said.
He added: "To conduct ESC research, ESCs must be derived from an embryo. The process of deriving ESCs from an embryo results in the destruction of the embryo.
"Thus ESC research necessarily depends upon the destruction of a human embryo."
But Judge Lamberth said an injunction would not "seriously harm" the embryonic studies because it did "not interfere with their [researchers'] ability to obtain private funding for their research".
The Dickey-Wicker Amendment, which Congress adds to budget legislation each year, played an important role in the case. The amendment bans the use of federal funds to destroy human embryos.
Judge Lamberth had been expected to hear groups on both sides of the case argue whether the new guidelines should be permanently blocked or allowed to continue.