WASHINGTON (AP) -- The new acting head of the Internal Revenue Service is telling lawmakers he'll do "everything possible" to make sure taxpayer money is spent wisely.

Acting Commissioner Danny Werfel says in his prepared remarks that it's a challenging time for the IRS.

The IRS has come under heavy criticism for expensive employee conferences and the targeting of conservative political groups that had applied for tax-exempt status.

A new report from the agency's watchdog says the IRS spent nearly $50 million on 225 employee conferences from 2010 through 2012.

Werfel is testifying before the House Oversight and Government Reform Committee.

The committee chairman, GOP Rep. Darrell Issa of California, says the conduct of IRS workers is unfairly making other federal employees look bad.