Operations at the ports of New York and New Jersey have been halted after thousands of workers staged a surprise walkout on Friday.

Over one thousand trucks were sitting idle at or near the terminals on Friday as the employees of the ports stopped working. The reason for the walkout was not clear, because "there were no major issues that we knew of to precipitate this," according to a Port Authority official.

“Right now the entire economy of the port is shut down,” said Jeff Bader, president of the Association of Bi-State Motor Carriers.

“We’re pulling all our trucks in and we’re heading home. We’ve missed hundreds and hundreds of exports. Containers are sitting there unmoved. You’re talking about hundreds and hundreds of thousands of dollars this thing has cost us,” he added.

Operations at the ports, however, are being restored and gates would open as scheduled on Monday, said the Authority who also urged workers to immediately return to work.

"We have heard your voices, we have heard your concerns, and we have taken action on your behalf," said the International Longshoremen's Association in a statement.

Several terminals were affected by the strike at the port system which is the third busiest in the United States and has 3,500 registered longshoremen.

A major retail trade group said a prolonged stoppage at the ports “could hamper economic growth and wreak havoc on spring deliveries,” and called for the parties to resolve the walkout quickly.

The New York & New Jersey is a key entry point for consumer goods, automobiles and building supplies. More than three million containers pass through the port each year.