(CNN) -- First lady Michelle Obama announced Wednesday that 270 private companies have pledged to hire 25,000 veterans and their spouses by the end of 2013.

The companies are part of a trade group called the American Logistics Association. Their commitment , she said, would fulfill one-quarter of the president's call for private sector companies to hire or train 100,000 veterans and military spouses by that time.

The first lady's announcement preceded a speech by President Barack Obama at a joint military base in Virginia, the third and last day of his bus tour aimed at pressuring Congress to pass his jobs package.

Obama discussed the importance of hiring American veterans during a stop at the Joint Base Langley-Eustis, calling the initiative a top priority.

"There are far too many veterans who are coming home and having to struggle to find a good job," Obama said. "It doesn't make any sense."

The president said "We ask our men and women in uniform to leave their families."

"The last thing you should have to do is fight for a job when you come," he said.

Obama called the companies' pledge a "testament " to their "commitment to this country."

He also called on Congress to pass his $447 billion jobs bill, calling the need to focus on jobs "an American responsibility."

Later in the afternoon, he is expected urge Congress to pass his plan while speaking to firefighters in North Chesterfield, Virginia.

The president continued hammering Republicans over their opposition to his jobs plan Tuesday, casting them as unwilling to support fair sacrifices in order to help a struggling middle class.

After visiting a computer lab and robotics workshop at a southern Virginia high school, Obama told a jammed auditorium at another school in Emporia that Republican opposition to his job plan makes no sense.

Republicans want to roll back environmental and financial regulations instead of taking concrete steps to create jobs, Obama said.

"That is a plan, but it's not a jobs plan," he said of a GOP counter-proposal to his jobs plan. "It's a plan to go back to doing the exact thing that we were doing before the financial crisis that put so many people out of work."

He urged the crowd to share its sentiment with lawmakers.

"Tell these members of Congress that they're supposed to be working for you, not special interests," he said. "..They need to deliver because they're not delivering right now."

In an interview with ABC's Jake Tapper, Obama said his package would bring 1.9 million new jobs.

"We can put teachers back in the classroom. We can put construction workers back on the job rebuilding our roads, bridges and schools," the president said. "We know that would work. I'm not worried about the long-term prospects of this economy because we still have the best universities in the world, the best workers in the world."

The trip promoting the jobs bill comes after Senate Republicans blocked consideration of the plan last week. Democrats are promising to force votes on individual components of the plan, starting with $35 billion for states and localities to hire more teachers and first responders while preventing current ones from being laid off.

That part of the plan could come up for a vote before the end of this week.

For their part, GOP leaders accused the president of trying to divide the country for his own short-term political gain while repeating what they've characterized as a failed 2009 economic stimulus plan.

"It's no secret that the vast majority of Americans aren't happy with Washington right now," said Senate Minority Leader Mitch McConnell, R-Kentucky. "It's also no secret that the president of the United States is trying to use this displeasure with Washington for political gain. And I think that's a pretty sad commentary on the state of affairs over at the White House these days."

Sen. John McCain, R-Arizona, whom Obama defeated in the 2008 election, has said the president is using a taxpayer-funded trip for campaigning.

Republicans are at odds with Democrats over how to pay for the plan. GOP leaders oppose a provision that would fund the measure through a 5.6% surtax on annual incomes over $1 million.

They have accused the president of engaging in "class warfare," while Democrats say wealthier Americans need to share in the cost of fiscal responsibility.

On Monday, a Senate Democratic leadership aide told CNN that Democrats will seek a 0.5% surtax on annual incomes over $1 million to pay for the component of Obama's jobs bill dealing with teachers and first responders.

However, a top Senate Republican leadership aide immediately responded that Republicans -- and some Democrats -- probably would not be willing to go along with a tax increase to pay for the measure.

Among other things, Obama's overall blueprint includes an extension and expansion of the current payroll tax cut, an extension of jobless benefits, new tax credits for businesses that hire the long-term unemployed and additional money to help save and create jobs for teachers and first responders such as firefighters.

CNN's Ted Barrett, Kate Bolduan and Virginia Nicolaidis contributed to this report.