WASHINGTON (AP) — The average long-term U.S. mortgage rate fell this week, tracking Treasury yields that have retreated since a deal to end the war with Iran was announced.

The benchmark 30-year fixed rate mortgage rate fell to 6.47% from 6.52% last week, mortgage buyer Freddie Mac said Thursday. One year ago, the average rate was 6.81%.

Borrowing costs on 15-year fixed-rate mortgages, often sought by borrowers refinancing a home loan, also came down this week. That average rate fell to 5.81% from 5.84% last week. A year ago, it was at 5.96%, Freddie Mac said.

Mortgage rates are influenced by several factors, from the Federal Reserve’s interest rate policy decisions to bond market investors’ expectations for the economy and inflation. They generally follow the trajectory of the 10-year Treasury yield, which lenders use as a guide to pricing home loans.

With inflation still well above the Federal Reserve’s 2% target, officials at the U.S. central bank left the benchmark interest rate where it was on Wednesday. It was the first meeting with new Fed Chair Kevin Warsh, who replaced Jerome Powell after his eight-year run as the U.S. central bank’s leader.

A number of Fed policymakers said they are actually willing to consider at least one interest rate hike this year.

Rates have been mostly trending higher since the conflict between the U.S. and Iran began in late February, disrupting the flow of crude oil from the Persian Gulf to customers worldwide. That’s sent oil prices sharply higher, helping drive up inflation, bond yields and mortgage rates.

However, earlier this week, the U.S. and Iran came to a tentative agreement to end the war and allow Iran to open the Strait of Hormuz and sell its oil freely.