 -- President-elect Donald Trump lashed out today against the movement to force general election vote recounts in three states that were critical to his Electoral College victory, saying that the efforts were "sad."

Trump, who on numerous occasions before the election claimed the electoral system was "rigged" and in 2012 questioned the integrity of the Electoral College after Mitt Romney's loss to Barack Obama, dug in his heels this weekend in a series of tweets against Green Party–backed efforts to recount the votes in the key states of Wisconsin, Michigan and Pennsylvania, where Trump narrowly defeated Hillary Clinton.

Clinton's campaign announced on Saturday that it would participate in the recount, although campaign general counsel Mark Elias said in a post on Medium that the campaign looked into the matter but has not found "any actionable evidence of hacking or outside attempts to alter the voting technology."

In his tweet storm, Trump criticized the Clinton campaign's participation by using her words against her.

"Hillary Clinton conceded the election when she called me just prior to the victory speech and after the results were in. Nothing will change," Trump started.

He highlighted her comments about accepting the results of an election: She criticized him in their third debate for implying that he might not concede the election if defeated, and he quoted that answer as well as her concession speech.

"So much time and money will be spent -- same result! Sad," Trump said in a tweet after quoting Clinton.

On Saturday, Trump called the recount efforts a "Green Party scam to fill up their coffers" in a tweet and then went on to attack the Democrats.

"The Democrats, when they incorrectly thought they were going to win, asked that the election night tabulation be accepted. Not so anymore!" he said.

Elias said in his statement Saturday that the campaign was participating in the recount effort because it has an obligation to the people who voted for Clinton to send legal representation to any court proceedings and have a presence where any recount efforts might take place.

Former Green Party presidential candidate Jill Stein said Friday the party raised more than $4 million in three days to support recount efforts in Wisconsin, Michigan and Pennsylvania.

Stein maintained that her activities are in no way intended to benefit Clinton, whom strongly criticized during the 2016 campaign.

George Martin, a former co-chairman of the Wisconsin Green Party who's involved in Stein's recount effort, said the party has been approached by computer scientists, election lawyers and other experts advocating vote recounts because of what they see as persuasive evidence of election result tampering. So far, no verifiable proof of tampering or hacking has been made public.

He said the recounts are not meant to change the election's outcome but are a check on the process of counting votes.

ABC News' Alexander Mallin and Veronica Stracqualursi contributed to this report.