On Wall Street, the S&P 500 edged 0.08 per cent lower on Thursday, marking its first four-day losing streak of 2018.
It hit a session low soon after the New York Times reported that US Special Counsel Robert Mueller had issued a subpoena for documents related to US President Donald Trump's businesses.
That added to growing US political uncertainties following the recent departure of two key officials, former Secretary of State Rex Tillerson and top economic advisor Gary Cohn, from the Trump administration.
The report earlier this week that Mr Trump is seeking to impose tariffs on up to $60 billion of Chinese imports cemented investor concerns that the administration is increasingly leaning towards protectionism.
"It seems as if for Trump, only 'America First' policies are left to boost his popularity and to get re-elected," said Hiroko Iwaki, senior strategist at Mizuho Securities.
"It is hard to expect political uncertainties to disappear soon. That will underpin bonds," she added.
US Treasuries yield stood little changed at 2.826 per cent in Asia after having hit near two-week low of 2.797 per cent.
Political uncertainties are not unique just to the United States. In Japan, Prime Minister Shinzo Abe is under pressure for suspicions of a cover-up in the government's controversial land sale.
In the currency market, rising risk aversion pushed the dollar lower against the safe haven yen to 106.22 yen down 0.1 per cent in early Asian trade.
The euro was little changed at $1.2303 , having slipped 0.5 per cent the previous day.
Oil prices were little changed after ending choppy Thursday trade higher as the International Energy Agency said global oil demand is expected to pick up this year, but warned supply is growing at a faster pace.
Brent futures stood flat at $65.11 per barrel.