WASHINGTON (Reuters) - The United States' trade deficit surged to its highest level in 12 years in 2020 as the COVID-19 pandemic disrupted the flow of goods and services.

The Commerce Department said on Friday that the trade deficit jumped 17.7% to $678.7 billion last year, the highest since 2008. Exports of goods and services tumbled 15.7% to their lowest level since 2010. Imports of goods and services dropped 9.5% to a four-year low.

The plunge in exports contributed to the economy shrinking 3.5% last year, the biggest drop in gross domestic product since 1946. Trade flows have been gradually improving. For December, the trade deficit narrowed 3.5% to $66.6 billion .

Economists polled by Reuters had forecast the trade gap would shrink to $65.7 billion in December.

Imports of goods rose 1.5% to $217.7 billion in December. Goods exports shot up 4.7% to $133.5 billion.

(Reporting By Lucia Mutikani; Editing by Chizu Nomiyama)