Donald Trump at a rally in Pennsylvania. Jeff Swensen/Getty Image President-elect Donald Trump seemed to offer more detail about his positions on Russia and China under his incoming administration.

Trump left open the possibility that the US could reconsider its adherence to the "One China" policy during an interview with The Wall Street Journal published Friday night.

The policy was established decades ago, in part to support diplomatic ties between China and the US.

Trump told The Journal any new developments between the US and China might hinge upon China's trade and currency practices, which the president-elect has characterized as unfair to the US.

Trump rattled Washington and China shortly after he won the election when he took a congratulatory call from Taiwan's President Tsai Ing-wen, the first direct communication between US and Taiwanese leadership in more than 30 years

US-Russia relations

On Russia, Trump told The Journal he would consider keeping in place new sanctions against Russia — which President Barack Obama announced late last year in response to Russia's election-related cyberattacks against the Democratic Party.

Trump said sanctions against the Kremlin could remain intact "for at least a period time" under his presidency. The new sanctions Obama outlined in December included the expulsion of 35 Russian diplomats from the US, who were promptly sent packing.

Trump suggested continued sanctions against Russia may not make sense under certain circumstances.

"If Russia is really helping us, why would anybody have sanctions if somebody’s doing some really great things?," the president-elect asked the newspaper.

It was unclear what Trump meant by "really great things." The president-elect has repeatedly exalted Russia during and after the election, and applauded Russian President Vladimir Putin. The day after Obama announced the new sanctions against Russia, Trump praised Putin again, saying Putin's response to the sanctions — that Russia would not retaliate, in hopes of friendlier ties with the Trump administration — was a "great move."

"I always knew he was very smart," Trump said of Putin.

U.S. President Barack Obama holds a press conference at the conclusion of the APEC Summit in Lima, Peru November 20, 2016. REUTERS/Kevin Lamarque

Condemning Russia

Trump's platitudes came against a backdrop of Republican and Democratic condemnation of Russia and Putin over the cyberattacks.

House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell issued statements slamming Russia, Sen. John McCain of Arizona said "every American should be alarmed by Russia's attack on our nation."

Sen, Lindsey Graham of South Carolina torched Putin and demanded "crippling sanctions" against the Kremlin. Obama called Russia's cyber activities against the US a "national emergency."

Putin has denied any wrongdoing.

Trump recently acknowledged that Russia was indeed behind the cyberattacks, but attempted to publicly dress down the US intelligence community as well, accusing the nation's top spy agencies of leaking info about the Russia hacking investigation to journalists.

The bipartisan Senate Intelligence Committee announced Friday it would investigate Russian intelligence operations in the US.

Committee chairman Sen. Richard Burr, who is a Republican from North Carolina, and vice chairman Sen. Mark Warner, a Democrat from Virginia, said in a statement: "We believe that it is critical to have a full understanding of the scope of Russian intelligence activities impacting the United States."

The committee plans to interview senior officials of both the Trump and Obama administrations and may issue subpoenas, Reuters reported.

Donald Trump. Evan Vucci/AP Photo

The Trump dossier

Trump's one-sided battle with the US intelligence community continued this week, with the publication of a file that contained unverified research on Trump, intended to draw links between Trump and Russian operatives.

During a long-awaited news conference on Wednesday, Trump and his advisers attempted to scold reporters they accused of spreading details about the dossier.

The incoming president revived his attacks Friday in a raging early morning tweetstorm:

"It now turns out that the phony allegations against me were put together by my political opponents and a failed spy afraid of being sued," Trump tweeted. "Totally made up facts by sleazebag political operatives, both Democrats and Republicans — FAKE NEWS!"

He continued: "Russia says nothing exists. Probably released by 'Intelligence' even knowing there is no proof, and never will be. My people will have a full report on hacking within 90 days!"

Trump is set to be inaugurated as the 45th US president on January 20.