According to administration officials, in the past few months North Korea did offer to halt exports of missiles and related technologies.
Crude oil prices rose after Iraq halted exports in a dispute with the United Nations.
In November 2000, Chinese and American officials reached agreement that China would halt such exports.
A disagreement with the United States over tin prices halted exports temporarily and caused a decline in income that further hurt the economy.
Drug experts said the raids on the labs almost halted exports of cocaine from Bolivia for a short time last year.
The imposition of international sanctions against Iraq, its largest trading partner, forced Jordan to halt vital exports.
Late last year, Baghdad halted exports for several weeks before gradually increasing them again.
Although technology companies aren't saying much officially about this, the Journal says some will, rather than surrender source code, simply halt exports to China.
The move will not halt Brazilian exports immediately, because many exporters have received registration for shipments abroad up to a year in advance.
A stronger yen tends to halt Japanese exports by making them more expensive overseas.