President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE said Wednesday that he intends to fight "all the subpoenas" issued by the House, setting up a drawn-out battle between the White House and congressional Democrats.

"We're fighting all the subpoenas," Trump told reporters as he left the White House for a conference in Atlanta on opioid abuse.

He dismissed a subpoena from the House Judiciary Committee for testimony from former White House counsel Don McGahn as "ridiculous."

"We have been, I have been the most transparent president and administration in the history of our country by far," Trump said.

The president asserted that Democrats are investigating his administration and issuing subpoenas for political reasons, suggesting it would help the party in the 2020 election.

"Look, these aren't impartial people," he said. "The Democrats are trying to win 2020. They're not going to win with the people that I see, and they're not going to win against me."

"The only way they can luck out is by constantly going after me on nonsense," he added.

Trump and other White House officials have indicated in recent days they would fight Democratic oversight efforts, but Wednesday's comments provide the clearest indication yet that the two sides are headed for a prolonged standoff that could be decided in the courts.

Trump told The Washington Post on Tuesday that he saw "no reason" to comply with the House subpoenas, arguing that cooperation with special counsel Robert Mueller Robert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE's investigation into Russian interference in the 2016 election was sufficient.

The president has in recent days excoriated Democrats for continuing with investigations into his administration and him personally in the wake of Mueller's report.

In the redacted document, investigators did not establish that the Trump campaign colluded with the Russian government during the 2016 election, but did not exonerate Trump on the question of obstruction of justice.

Investigators instead detailed 10 episodes they reviewed for potential obstruction by the president, with Mueller saying that Congress has the authority to conduct potential obstruction probes.

Democrats have pressed for the full, unredacted version of Mueller's report, and have pledged to carry on with investigations into the president's taxes, potential abuse of power and the White House security clearance process, among other areas.

Trump on Wednesday argued the Mueller investigation was thorough enough to eliminate the need for congressional probes. He suggested Mueller's team may have reviewed his taxes and finances, another target of Democratic document requests.

"I say it’s enough," Trump said. "Get back to infrastructure. Get back to cutting taxes. Get back to lowering drug prices."

The House Judiciary Committee is seeking testimony from McGahn, who cooperated extensively with Mueller and has been the subject of Trump's ire as a result.

According to investigators, McGahn characterized Trump’s orders to oust Mueller as “crazy shit” and is depicted as telling Trump in a private conversation he was keeping notes because he is a “real lawyer” after the president challenged his decision to tell Mueller about efforts to get rid of the special counsel.

The White House has also told former White House personnel security director Carl Kline not to appear before the House Oversight and Reform Committee as part of the panel's investigation into the administration's security clearance process.

Oversight and Reform Committee Chairman Elijah Cummings Elijah Eugene CummingsBlack GOP candidate accuses Behar of wearing black face in heated interview Overnight Health Care: US won't join global coronavirus vaccine initiative | Federal panel lays out initial priorities for COVID-19 vaccine distribution | NIH panel: 'Insufficient data' to show treatment touted by Trump works House Oversight Democrats to subpoena AbbVie in drug pricing probe MORE (D-Md.) on Tuesday indicated he would seek a vote to hold Kline in contempt of Congress.

— Updated at 11:50 a.m.