WASHINGTON, April 18 (Xinhua) -- U.S. economic outlook remained positive, while tariff concerns are casting cloud over the outlook, a report released by the Federal Reserve showed on Wednesday.

"Outlooks remained positive, but contacts in various sectors including manufacturing, agriculture, and transportation expressed concern about the newly imposed and/or proposed tariffs," said the Fed in its latest survey on economic conditions in March and early April, known as the Beige Book.

U.S. has levied additional tariffs on steel and aluminum products imported from other countries and threatened to impose 25 percent tariff on a combined figure of about 150 billion U.S. dollars of goods imported from China.

Upon the levy of the new tariffs, there were widespread reports that steel prices rose, sometimes dramatically, said the Fed.

"Businesses generally anticipate further price increases in the months ahead, particularly for steel and building materials," it noted.

American companies continued to note difficulty in finding qualified workers due to labor shortages, according to the report. However, most Districts reported wage growth as only modest.

"Upward wage pressures persisted but generally did not escalate," said the Fed.