European markets opened slightly higher on Tuesday morning, tracking modest overnight gains after data showed China's economy grew slightly more than anticipated in the first quarter.

Asian equities edged higher on Tuesday, after official data showed the world's second-largest economy grew at 6.8 percent during the first three months of the year. MSCI's index of Asia-Pacific shares, excluding Japan, was around 0.1 percent higher on the news.

On Saturday, the U.S., U.K. and France launched more than 100 missiles targeting Syrian government sites in a response to a likely poison gas attack in the country earlier this month.

Meanwhile, on the data front, the euro zone's largest economy is expected to report its monthly economic sentiment index on Tuesday. Germany's ZEW institute is poised to release the data for April at around 10 a.m. London time.