WASHINGTON — Despite signs of stepped-up White House involvement, a bipartisan compromise over expanded background checks for gun buyers remained elusive Tuesday as a Senate panel prepared for votes this week on curbing firearms.

Sen. Tom Coburn, R-Okla., has been the lead Republican negotiating with Sen. Chuck Schumer, D-N.Y., and other Democrats over a compromise background-check measure. They’ve been stuck over Democrats’ insistence that records be kept on sales between private individuals.

Coburn spoke at the White House last week with Vice President Joe Biden on guns and other issues, and received a phone call Monday from President Obama in which they discussed “everything,” the senator said. He declined to provide details.

“We’re very close,” Coburn said Tuesday in a brief interview.

Others were less optimistic. Senators and staff were talking constantly in search of a bipartisan pact but have not resolved the dispute, according to aides and lobbyists on both sides of the issue. They spoke on condition of anonymity because they were not allowed to describe the status of private talks publicly.

The Senate Judiciary Committee plans to consider gun control bills Thursday.

Currently, background checks are required for sales by federally licensed gun dealers. Obama, Schumer and other Democrats want to expand that to nearly all transactions, such as private sales at gun shows and online. The record checks are performed in an effort to keep criminals, people with mental health problems and others from getting firearms.

Democrats say records must be kept of private sales because that would be the only way to verify that background checks for those transactions were conducted. Supported by the National Rifle Association, many Republicans have objected, saying that would be a step toward a government registry of gun owners – something they oppose and the White House has said will not happen.