Green Party presidential candidate Jill Stein's recount effort in Pennsylvania is over, but her campaign vowed to keep fighting in federal court to make it easier to verify vote totals in the state.

Stein, in a conference call with reporters Tuesday, accused Commonwealth Court of "financial extortion" for requiring her campaign to post $1 million bond while requesting a statewide recount of the vote.

Stein dropped that state case and went to federal court, where a judge on Monday rejected her effort, saying that it came too late and that she offered no evidence to support her theory that the state's vote-tabulation computer systems may have been hacked.

Stein lawyer Jonathan Abady said her campaign would not appeal U.S. District Judge Paul S. Diamond's ruling rejecting her request to order the state to conduct a recount.

Abady said Stein would continue with the federal lawsuit in Pennsylvania and called the state's Election Code requirements for a recount "Byzantine and unworkable."

Stein had also launched recount efforts in Michigan and Wisconsin, which have ended.

Pennsylvania's Department of State certified the results of the Nov. 8 election on Monday after Diamond's ruling was issued.

The state's Electoral College members are due to gather in Harrisburg on Monday to vote for president. Republican Donald Trump defeated Democratic nominee Hillary Clinton in Pennsylvania by 0.73 percent, a margin of 44,286 votes.

Stein won 0.82 percent of the vote, receiving 49,941 votes.

Stein said during the conference call that Trump's unsubstantiated claims before the election that the voting was "rigged" against him had "enormous resonance." She said her recount effort, unsupported by any evidence of voting system hacking, was different.

"They are insecure," Stein said of the voting systems. "They are poorly protected. They are essentially without modern security functions."

Diamond ruled that a computer expert for Stein's campaign testified in a hearing Friday that he had " 'no evidence' that any voting machine was hacked and that the election outcome was 'probably not' the result of a hack."

Pennsylvania Republican leaders held a news conference Tuesday in Northeast Philadelphia to denounce Stein's recount efforts in the state.

Lawrence Tabas, the party's general counsel, accused Stein of attempting to "create chaos and to create doubt" to disrupt the Electoral College vote."

"It failed because the courts in Pennsylvania recognized the claims as being baseless," Tabas said. "Today I say to you that Jill Stein owes an apology to every voter in Pennsylvania."

Tabas said the Republican Party was considering whether to seek payment from the Stein campaign for its legal fees.

Stein's campaign said Tuesday that it was ending a fund-raising drive that brought in $7.3 million for the multistate recount effort. The campaign said it spent $7.4 million in the three states, but may have some money returned by Michigan and Wisconsin.

"In the event of a recount surplus, the campaign will ask the more than 161,000 small donors how they want to spend the remaining funds, and have pledged to allocate the money to a set of nonpartisan election reforms and voting rights organizations based on the results of an online, ranked-choice vote," the campaign said in an email.