Donald Trump decried how he and Republican Party were treated "very badly" by Democrats.

US President Donald Trump said Wednesday that a battle with Democrats over his possible impeachment would likely go to the Supreme Court, after the White House said it would not cooperate with an ongoing probe.

Trump has repeatedly sought to discredit an impeachment inquiry over his possible abuse of power in pressuring Ukraine to dig up dirt on political rival Joe Biden.

"It probably ends up being a big Supreme Court case," Trump said, decrying how he and the Republican Party had been "treated very badly by the Democrats."