Prices for U.S. imports and exports increased 0.6 percent, respectively, for the second consecutive month in May, the U.S. Bureau of Labor Statistics reported on Thursday.

Prices for all imports in May continued the upward trend that began in August 2017. The May advance followed a 0.6-percent rise from the previous month.

The price index for overall imports increased 4.3 percent for the year ending May, the largest 12-month advance since the index rose 4.7 percent in February 2017. The May over-the-year advance was largely driven by higher fuel prices although nonfuel prices also increased over the past year.

Import fuel prices rose 4.9 percent in May, after a 4.1-percent advance in April. The May rise was the largest monthly increase since the index rose 9.8 percent in November 2017. Prices for import fuel increased 28.6 percent over the past 12 months, driven by a 31.9-percent rise in petroleum prices. In contrast, natural gas prices fell 18.5 percent over the past year.

Nonfuel import prices increased 0.2 percent for the second consecutive month in May and have not recorded a monthly decline since the index decreased 0.2 percent in December 2017. Nonfuel prices advanced 1.9 percent over the past year, primarily led by higher prices for nonfuel industrial supplies and materials.

Prices for all exports increased in May, led by higher prices for both agricultural and nonagricultural exports. The price index for overall exports advanced 4.9 percent between May 2017 and May 2018, the largest 12-month increase since the index rose 6.3 percent in October 2011.

The price index for agricultural exports advanced 1.6 percent in May following a 1.2-percent decline the previous month. Prices for agricultural exports also rose over the past 12 months, advancing 4.9 percent.

Nonagricultural export prices advanced 0.5 percent in May. Prices for overall nonagricultural exports increased 4.9 percent for the year ending May.