The lender will have to stop new loans and insurance coverage, which means "lost sales, lost customers, and lost opportunities" for U.S. exporters, Obama said in an op-ed piece in the Boston Globe.

Conservative Republicans want to shut down the lender, which they argue provides corporate welfare to U.S. companies that count on its support, such as Boeing Co. and General Electric Co.

Democratic lawmakers and exporters are pinning their hopes on attaching legislation to revive the trade bank to a highway and rail funding bill that will be considered in July.

"Strong majorities of Democrats and Republicans have said they'd vote 'Yes' to reauthorize the bank. Congressional leaders just need to call a vote," Obama said.

In a conference call on Tuesday with business leaders, labor unions and other officials, Obama expressed frustration with the lapse.

"He said the White House would be working hard to get this corrected," said Don Nelson, president of Pro-Gauge Technologies Inc., a Bakersfield, California, manufacturer of oilfield equipment.

"It was President Obama really frustrated that Congress allowed the Ex-Im Bank to lapse, to unilaterally disarm American exporters. He encouraged all of us to continue fighting for what's right and to try to get the bank reauthorized," said Nelson, who was on the call and spoke to Reuters.

Obama noted there are 85 export credit agencies similar to the Ex-Im Bank around the world.

"They're all fighting for sales and export-backed jobs," he said in his op-ed, noting past congresses and presidents have supported the bank over its 81-year history. "Why wouldn't we do the same?"

The bank will not close its doors on July 1. Its administrative budget, paid from fees it collects, is authorized through Sept. 30, the end of the fiscal year.