Export volume at the Port of Oakland spiked in May despite the ongoing U.S.-China trade war and recent tariff increases, port officials said June 14.

May exports, primarily to Asia, rose 8.4 percent compared to the year-ago period, with the port processing a total of 78,070 export containers. Imports rose 4.2 percent during the month, according to port officials, who said the port handled the equivalent of 85,964 20-foot import containers

Oakland officials said the port has improved year-over-year import and export performance for three straight months despite analysts' warnings of a trade decline in the face of the country's ongoing trade war with China. The news follows similar reports from the Ports of Los Angeles and Virginia, both of which reported record import volumes in May as organizations prepared for the upcoming peak holiday season while attempting to stay ahead of more tariff increases. In May, President Trump raised tariffs on $200 billion worth of Chinese goods to 25 percent and prepared to raise duties on an additional $300 billion in Chinese imports. China shot back with tariff increases on $60 billion in U.S. goods.

Oakland officials said its customers are turning to China's neighbors, including Vietnam, Taiwan, South Korea, and Japan, to avoid the trade war hurdles, as both exporters and importers turned to those markets to purchase products previously purchased in China.

"Logic tells us that at some point, tariffs should drive down cargo volumes because they're making international trade more expensive," Port of Oakland Maritime Director John Driscoll said in a statement about May cargo volume. "But our customers have so far defied conventional wisdom by finding new markets for their products."

Oakland's total cargo volume last month-imports, exports, and empty container returns-increased 9 percent, port officials said. The volume of empty containers shipped back to Asian markets for reuse climbed 17.5 percent. Oakland said it set a record by handling 2.55 million cargo containers in 2018. Through the first five months of 2019, volume is up 5.5 percent compared to last year.

Port officials also emphasized the uncertain trade outlook, especially in light of even higher tariffs on Chinese goods being imposed this month. Officials said the port will "pay close attention to June cargo volume to learn if heightened tariffs dampen trade."