The U.S. Internal Revenue Service announced new steps on Thursday aimed at getting taxpayers hiding money in offshore accounts to pay up, promising not to file criminal charges for those who voluntarily fess up to hiding money overseas.

This is a chance for people to come clean on their own, IRS Commissioner Doug Shulman told reporters.

While promising not to prosecute criminal charges, the IRS would impose penalties and interest on past due taxes, he said.

Switzerland agreed earlier this month to relax its strict bank secrecy rules and cooperate more on tax evasion to fend off a global crackdown on tax havens. The country has been under pressure because of an IRS tax fraud investigation targeting UBS AG

IRS memos sent to agency examination staff said offshore tax cases should receive priority treatment.

Offshore cases sent to the field are work of the highest priority, said one document, which was made public by the IRS. Examiners should utilize the full range of information gathering tools in properly developing offshore issues with special emphasis on detecting unreported income. This includes interviewing taxpayers, making third-party contacts and timely issuing summonses to taxpayers and third parties.

(Editing by Andre Grenon)