Hong Kong and mainland stock markets opened flat on Friday, as a call between Beijing and Washington offered little clarity to ease ongoing trade tensions.

The SAR's benchmark Hang Seng Index rose 34.6 points, or 0.14 percent, to open at 23,941, while the blue-chip CSI300 Index on the mainland edged down 0.1 percent.

President Xi Jinping and his US counterpart Donald Trump confronted weeks of brewing trade tensions and a battle over critical minerals in a leader-to-leader call on Thursday, leaving key issues unresolved for future talks.

"Market reaction is low key as the discussion between the two leaders lacked real details outside of agreeing to new rounds of tariff talks," UBS analysts said in a note.

"With no clear signs the call will cool trade tensions, headline risk remains top of mind amid the ongoing tariff rifts."

Chinese tech ADRs were muted after the call, up only 0.85 percent overnight in New York session. (Reuters/Xinhua)