WASHINGTON (AP) — The U.S. government is running up against its $16.4 trillion borrowing limit and is taking steps to avoid default.

Reaching the limit Monday sets up another dispute between the White House and Congress over taxes and spending in the new year.

Treasury Secretary Timothy Geithner says the government will take a series of accounting measures to avoid defaulting on its debt. On Monday, it suspended the issuance of new debt for two government retirement funds. That step won’t impact current retirees.

Last week, Geithner said the measures would save about $200 billion. That would typically avoid default for about two months. But Geithner said it is difficult to predict how long default can be avoided this time because of ongoing budget talks.