The yen was 0.1% firmer at 110.200 to the dollar, having pulled back from a two-week low of 110.675 plumbed on Tuesday.
The Japanese currency also rose 0.15% against the euro, added 0.2% versus pound and advanced 0.3% on the Australian dollar.
Reports that the United States could impose restrictions on Chinese technology company Hikvision renewed market jitters about trade on Wednesday, reversing a relief rally that followed Washington's move to temporary ease curbs against Huawei Technology Co Ltd.
A deepening Brexit crisis also sapped investor risk sentiment. Pressure on British Prime Minister Theresa May to resign increased after her new Brexit gambit backfired and as a key ally resigned from her cabinet.
"While the currency market appears to have mostly priced in May's eventual resignation, it is now trying to work out who might replace her," said Yukio Ishizaki, senior currency strategist at Daiwa Securities.
"The possibility of someone like Boris Johnson replacing May will heighten prospects of a no-deal Brexit and likely lead to further 'risk off.' The mood in the market is darkening as the Brexit ongoings add to prevailing U.S.-China worries."
The pound dipped 0.07% to $1.2652 after slipping to $1.2625 overnight, its lowest since Jan. 4.
The dollar index against a basket of six major currencies was little changed at 98.105, its rise earlier in the week to a one-month high of 98.134 stalling as U.S. yields declined amid the risk aversion.
"News related to the stand-off between the United States and China will remain the main driver of currencies," said Junichi Ishikawa, senior FX strategist at IG Securities in Tokyo.
In particular focus are headlines that could be negative for the technology sector, which in turn would lift the yen and the Swiss franc, he said.
The Swiss franc, a safe-haven along with the yen, was a shade higher at 1.008 francs per dollar after advancing 0.15% on Wednesday.
The euro was flat at $1.1150, in close range of a 2-1/2-week low of $1.1142 brushed on Tuesday ahead of the May 23-26 European parliamentary election.
The German and euro zone manufacturing purchasing managers' index (PMI) releases due later on Thursday may impact the single currency.
The Australian dollar, sensitive to shifts in risk sentiment, nudged down 0.2% to $0.6870.
(Reporting by Shinichi Saoshiro; Editing by Sam Holmes)
By Shinichi Saoshiro