Growing concern about the national debt impacted home borrowing rates this week. Mortgage rates track the benchmark 10-year Treasury yield, which climbed higher as bonds sold off

The average rate on a 30-year mortgage in the U.S. climbed this week to its highest level since mid-February, a setback for home shoppers that threatens to slow sales further this spring homebuying season.

Mortgage rates inched higher over the last week, delivering yet another blow to a lackluster spring housing market.