A former campaign adviser for John Kasich said Thursday that he’s backing out of a $350,000 contract to lobby against sanctions on behalf of a Russian state-owned nuclear energy company, vowing instead to put a "laser focus" on helping prevent President Trump's re-election.

John Weaver, who was the top strategist on the 2016 presidential campaign of Kasich, the Republican former governor of Ohio who has frequently been at odds with President Trump, announced his decision on Twitter after drawing heat for accepting the lobbying gig.

FORMER KASICH ADVISER TAKES $350G JOB LOBBYING FOR RUSSIA, REGISTERS AS FOREIGN AGENT: REPORT

“My attorney has contacted Tenam this morning & informed them I must reject this agreement. No funds were transferred, no actions taken," Weaver said, referring to the Russian company. "Now, I've got to get back to the barricades. Apologies for the momentary distraction.”

Weaver had signed a contract last month to lobby Congress and the Trump administration on behalf of Tenam Corp., a subsidiary of the Rosatom, the Russian state-owned nuclear energy company, for at least six months and registered as a foreign agent, Politico reported.

When news of the contract broke Wednesday, Weaver received heavy backlash from social media users who pointed out he had spent most of his career criticizing the Kremlin, most recently for its interference in the 2016 U.S. presidential election.

Weaver initially defended his new gig in a lengthy series of tweets late Wednesday, claiming he took the job working for Russia because he feared Trump’s “go-it-alone” policies would jeopardize U.S. national security interests, the U.S. economy and the world market.

CLICK HERE TO GET THE FOX NEWS APP

He announced a change of heart the following day, pledging to not let money distract him from his sole mission: ensuring Trump is not elected to a second term.

“While I fear the dangers of nuclear proliferation & know a stable uranium market is important to the USA's national & economic security -- & experts urged this -- my laser focus is on 2020 & playing any role -- major or minor -- in ensuring Trump serves only 1 term,” Weaver wrote Thursday.

“To allow anything to distract from that is a mistake. And I can recognize a mistake when I make it,” he said.

Kasich, Weaver's former boss, has said he would give consideration to opposing Trump in Republican primaries in 2020, but has not declared a candidacy for president.