Asia markets declined on Thursday as investors worried about the ongoing trade tensions between the United States and China. Mainland Chinese shares slipped on the day, as the Shanghai composite declined 1.36% to about 2,852.52 and the Shenzhen component fell 2.56% to 8,809.53. The Shenzhen composite also dropped 2.432% to approximately 1,503.37. Hong Kong's Hang Seng index declined 1.73%, as of its final hour of trading. Elsewhere, the Nikkei 225 in Japan slipped 0.62% to close at 21,151.14. Shares of index heavyweight and conglomerate Softbank Group plunged 5.3% after sources told Reuters that U.S. Justice Department staff have recommended blocking a deal between T-Mobile and rival Sprint. The Topix index also shed 0.36% to finish the trading day at 1,540.58. In South Korea, the Kospi fell 0.26% to close at 2,059.59, while Australia's declined 0.29% to finish its trading day at 6,491.80. Over in India, the Nifty 50 rose 0.7% after earlier hitting a new record high as vote counting was underway following the country's national elections. Most exit polls have pointed to incumbent Prime Minister Narendra Modi's coalition securing a majority.

Huawei suppliers tumble

Investors also continued to watch out for developments surrounding Chinese telecommunications giant Huawei, which has been blacklisted by the U.S. Shares of Huawei suppliers took a hit on Thursday amid the ongoing fallout. In Taiwan, contract manufacturing giant Hon Hai Precision Industry — commonly known as Foxconn — and chipmaker Taiwan Semiconductor Manufacturing Company both fell more than 3%. In Hong Kong, smartphone camera module and lens manufacturer Sunny Optical saw its stock plummet more than 7%, while Luxshare dropped 5.97% in Shenzhen. "Given Huawei's size and integral role in global supply chains, the consequences of US moves against the Chinese firm could be material, particularly if the dispute escalates," analysts at Investec Asset Management wrote in a note.

US-China trade

Overnight on Wall Street, shares slipped as investors kept an eye on developments between Beijing and Washington amid a recent escalation in trade tensions. U.S. Treasury Secretary Steven Mnuchin told CNBC's Ylan Mui on Wednesday that a trip to Beijing to resume trade negotiations has not been scheduled yet, reducing hopes of a speedy resolution to the trade war. "The rhetoric really has gone up very significantly in the past couple of weeks, obviously not just on the U.S.' side ... but also the China rhetoric, you know, coming out from policy circles and obviously now from the president as well," Steve Brice, chief investment strategist at Standard Chartered Private Bank, told CNBC's "Squawk Box." "It's not that this cannot be solved, right? It can be, but the rhetoric is picking up and that's making it harder, I think, to strike a deal in the short term," Brice said.

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