Oil and gold prices climbed while regional shares edged nervously higher on Wednesday as geopolitical tensions ratcheted up ahead of key U.S. inflation data.

The yen was mostly flat against the dollar, having unwound much of its gains following rare currency-market intervention by Japan and the United States.

The U.S. ​and Yemen's Iran-aligned Houthis reported separate attacks on shipping, while Asia was rattled by an early morning missile launch by North Korea. ‌Markets remained focused on U.S. consumer price index data later in the session for signals of timing for a potential Federal Reserve rate hike.

"Market sentiment is lukewarm amidst lingering geopolitical risk and as market participants head into U.S. CPI data," Kyle Rodda, a senior financial market analyst at Capital.com, wrote in a note.

"The lack of substantial news or ​progress in talks, with Iran doubling down on its commitment to govern the Strait of Hormuz, is keeping the risk for oil ​prices skewed to the upside and U.S. indices on hold," he added.

U.S. crude rose 0.89% to $83.94 a barrel, and ⁠Brent advanced to $89.60 per barrel, up 0.78% on the day. Both benchmarks settled more than $1 higher on Tuesday, marking their highest closes since July 31 and ​extending gains after jumping about 5% on Monday.

Spot gold gained 0.46% to $4,387.03 an ounce. MSCI's broadest index of Asia-Pacific shares outside Japan was up 0.5%, while Japan's ​benchmark Nikkei share gauge traded flat as the market reopened after a holiday.

Four crew members of an Egyptian-owned ship were killed in an attack by Houthis on Tuesday, Yemen's transport ministry said, while the U.S. military said it struck a container ship attempting to sail toward an Iranian port. The fatalities would mark the first from a Houthi strike ​on shipping since the Iran war began on February 28.

The war shows no signs of ending despite repeated claims from U.S. President Donald Trump ​of an imminent deal.

A North Korean ballistic missile fired off the Korean Peninsula's east coast came days ahead of major joint military exercises by Seoul and Washington long ‌denounced by ⁠Pyongyang. Meanwhile, Taiwan condemned planned naval drills between China and an Indonesian warship off the island's east coast.

Wednesday's CPI data will not capture the most recent rise in energy costs, but it could still prove instrumental in setting expectations for the Fed's meeting next month, with money markets showing an even chance of a hike .

Consumer prices are expected to edge up 0.1% in July after falling 0.4% in June, according to a Reuters poll. Annual CPI inflation ​is forecast to slow to 3.4% from ​3.5% a month earlier.

"Everyone's got ⁠their eyes on the CPI report," Skye Masters, head of markets research at National Australia Bank, said on a podcast. "If you do see the print coming in at zero, I think you'll obviously see a reasonable rally in ​Treasuries as the market unwinds expectations for the Fed tightening."

Markets are also increasingly pricing in an early ​rate hike in Japan, ⁠putting pressure on the nation's shorter-dated bonds. The yield on the 5-year Japanese government bonds rose to 2.1%, a record high, while the 2-year yield reached a 31-year peak of 1.63%.

The dollar index , which measures the greenback against a basket of currencies, rose 0.04% to 99.85. The euro was down 0.02% at $1.1538.

The Japanese yen ⁠weakened 0.03% ​against the greenback to 159.31 per dollar, remaining off last week's high of 155.20 after ​several suspected rounds of intervention. Sterling weakened 0.01% to $1.3501.

In early European trades, the pan-region Euro Stoxx 50 futures were down 0.15% at 6,563, German DAX futures fell 0.12% at 26,444, and ​FTSE futures lost 0.25% to stand at 10,825.

U.S. stock futures, the S&P 500 e-minis , were up 0.03% at 7,750.