U.S. President Donald Trump (R) speaks at a joint press conference with visiting Australian Prime Minister Scott Morrison at the White House in Washington D.C., the United States, on Sept. 20, 2019. Donald Trump on Friday defended himself against a whistleblower complaint on the president's alleged inappropriate interactions with a foreign leader, calling it "another political hack job" during a joint press availability with Scott Morrison. (Xinhua/Hu Yousong)

WASHINGTON, Sept. 20 (Xinhua) -- U.S. President Donald Trump on Friday defended himself against a whistleblower complaint on the president's alleged inappropriate interactions with a foreign leader, calling it "another political hack job."

During a joint press availability inside the Oval Office with visiting Australian Prime Minister Scott Morrison, Trump said that his conversations with leaders around the world were "always appropriate... at the highest level, always appropriate."

"It's just another political hack job. That's all it is," Trump said of the complaint.

Trump reportedly communicated with a foreign leader and made an unspecified "promise," which an unidentified intelligence official considered so troubling that the official filed a whistleblower complaint in mid-August with the inspector general for the intelligence community, an independent watchdog.

Trump said he didn't know the identity of the whistleblower. "I just hear it's a partisan person, meaning it comes out from another party."

At least part of the complaint involved Ukraine, The Washington Post and The New York Times both reported, citing anonymous sources.

House Democrats, according to the Post, have been probing a July phone call between Trump and Ukrainian President Volodymyr Zelensky to see whether Trump, and his attorney, Rudolph Giuliani, aimed to manipulate Kiev into helping his re-election campaign.

Trump told reporters that it didn't matter what he discussed with Zelensky and that the phone call was "a beautiful conversation."

The president's response came amid heightened tensions between the Congress and the White House over the scandal.

On Thursday, House Intelligence Committee Chairman Adam Schiff, a California Democrat, warned of possible legal action while lambasting Acting Director of National Intelligence (DNI) Joseph Maguire's decision to withhold the whistleblower complaint from the House committees.

"We do not have the complaint. We do not know whether the press reports are accurate or inaccurate about the contents of that complaint," Schiff told reporters. "We're determined to do everything we can to determine what this urgent concern is to make sure that the national security is protected."

Michael Atkinson, the inspector general, wrote in a letter to Schiff dated Sept. 17, "I set forth the reasons for my concluding that the subject matter involved in the Complaint's disclosure not only falls within the DNI's jurisdiction, but relates to one of the most significant and important of the DNI's responsibilities to the American people."