The Hang Seng Index rose 1.7 per cent to 21,271.95 as of 9.52am local time. The Hang Seng Tech Index gained 2.2 per cent.
On the mainland, the CSI 300 Index climbed 0.4 per cent and the Shanghai Composite Index added 0.6 per cent.
Electronics firms led the market higher. Personal-computer maker Lenovo Group advanced 5.5 per cent to HK$8.46 and BYD Electronic International rallied 4.3 per cent to HK$34.25. Alibaba Group Holding gained 3.7 per cent to HK$106.80 and Tencent Holdings added 1.6 per cent to HK$450.60.
The pause on duties includes smartphones, laptops and memory chips, though US President Donald Trump said the exemption was only temporary and that he would come up with separate tariffs on these items.
Elsewhere in Asia-Pacific, Japan’s Nikkei 225 climbed 1.4 per cent, South Korea’s Kospi rose 0.9 per cent and Australia’s S&P/ASX 200 added 1 per cent.