President Obama has time and again called the sequester a serious matter that will “cost us jobs.”

But on Friday, speaking to a crowd in Argonne, Ill., Obama sought to lighten the mood, cracking a joke before a seated crowd that he thought the sequester meant they “had to get rid of chairs.”

“Those of you who have chairs — I wasn't sure everybody had chairs — please feel free to sit down, I'm sorry. Everybody was standing,” he said. “I thought Argonne ... one of the effects of the sequester, you had to get rid of chairs.

“That's good, I'm glad we've got some chairs,” Obama added, after laughter from the crowd.

Obama traveled to Illinois on Friday to deliver remarks on an energy proposal. But he spent some time at the top of his speech discussing the impact of the sequester, which took effect two weeks ago.

“These cuts will harm, not help our economy,” Obama said at the Argonne National Laboratory near Chicago.

“One of the reasons I was opposed to these cuts is because they don't distinguish between wasteful programs and vital investments,” Obama said. “They don't trim the fat, they cut into muscle and into bone.”

The president's comments follow a three-day charm offensive on Capitol Hill, where Obama attempted to work with lawmakers on both sides of the aisle on deficit reduction, immigration and other issues.