The bureau said the trade gap rose from downwardly $40.1 billion in April to $45 billion in May on exports of $187.1 billion and imports of $232.1 billion.
From month to month, exports were down by $500 million and imports were up by $4.4 billion, said the bureau, which is part of the Commerce Department.
The largest trade gaps were familiar. The trade deficit with China rose from $24.1 billion in April to $27.9 billion in May. With the European Union, the gap shrank month to month from $12.4 billion to $10.8 billion. Trading with the Organization of Petroleum Exporting Countries slipped from $6.6 billion to $6.3 billion.
Deficits were also posted with Japan at $5.4 billion, Mexico at $5.3 billion, South Korea at $2.5 billion, India at $2.3 billion, Canada at $1.9 billion and Venezuela at $1.5 billion.
Major trading partners with which the United States runs a trade surplus is a shorter list with smaller numbers. Surpluses were posted with Hong Kong, Australia, Singapore and Brazil. The total surplus with these trading partners came to $6.5 billion, which was more than offset by the deficit with OPEC by itself.
Economists had expected the trade gap to remain steady at about $40 billion.