Republican presidential candidate Carly Fiorina slammed rival Hillary Clinton on Sunday, saying the Democratic front-runner has “gotten every single foreign policy challenge wrong.”

Fiorina, who appeared on "Fox News Sunday," also took a shot at GOP candidate Donald Trump.

“Donald Trump is a big Christmas gift wrapped up under the tree” for the Clinton campaign.

“She desperately hopes she runs against Donald Trump,” Fiorina said. “I, however, am the lump of coal in Mrs. Clinton’s stocking and she desperately hopes she does not run against me.”

“She can beat Donald Trump,” Fiorina said. “Donald Trump cannot beat Hillary Clinton. I think it’s very clear.”

Fiorina, once a breakout star of the GOP who fought her way from the low-polling undercard debates to the primetime stage, has been having trouble in the past few weeks maintaining her momentum.

During last week's fifth Republican debate, Fiorina came under fire after she said she would bring back the “warrior class” to fight the Islamic State and claimed several high-ranking generals had left the military because they didn’t agree with President Obama’s political policies. 

Gen. Jack Keane, a Fox News contributor and one of the generals she said quit, actually retired before Obama took office. Fiorina also said Gens. David Petraeus and Stanley McChrystal resigned because they disagreed with the administration; but, in fact, Petreaus’ retirement came following revelations he shared classified information with his alleged mistress and biographer while McChrystal called it quits after he was quoted criticizing Obama in a “Rolling Stone” article.

Fiorina was also pressed by host Chris Wallace about a digital ad paid for by a super PAC supporting Fiorina that links her to Margaret “Iron Lady” Thatcher, the first female prime minister of Britain.

“Mrs. Fiorina, respectfully, isn’t that a little over the top?” the anchor asked.

“Many people have commented on the comparison and I’m flattered by it, frankly,” she said. “Margaret Thatcher was a great leader for her nation at a pivotal and perilous time.”

When asked by Wallace about her stagnant poll numbers, Fiorina said she was “happy” with her position and that she is where she wants to be. 

She quipped, “People make up their minds late, and if the polls at this stage and in earlier states were true we would have had President Howard Dean, President Rudy Giuliani, and by the way, we would have already had President Hillary Clinton.”