Top US and Chinese officials met on Friday to wrap up a week of talks that have seen the two sides struggle to detail how to bridge deep differences on China's role in global commerce. US President Donald Trump is scheduled to raise tariffs to 25 percent from 10 percent on $200 billion of Chinese imports on March 1 unless a deal is reached.

Treasuries are safe-haven assets that benefit in times of political and economic volatility. But a risk-off trend was not evident in other financial markets. The dollar index, another safe haven, was modestly lower, while the S&P 500 index and the Dow Jones Industrial Average, both risk assets, were up.

Investors suggested that the turn downward in yields was partially attributable to remarks made by members of the Fed at a conference in New York on Friday.

"We've seen a pretty strong rally across the Treasury market in response to comments from some Fed officials, most importantly Richard Clarida with respect to their review of policy," said Bill Northey, senior investment director at US Bank Wealth Management.

The Fed will keep an open mind as it begins a broad review this year of its monetary policy framework that could result in changes to how it goes about ensuring that prices remain stable and employment plentiful, Fed vice chair Richard Clarida said at the US Monetary Policy Forum.

Of particular importance, Northey said, was discussion of "the potential for thinking about the symmetrical view of inflation targeting and whether that may put more formalized methodology around allowing the economy to run hot for a makeup of what has been a perpetual undershoot of their 2 percent target for the past several years."

Despite a US unemployment rate that has plumbed its lowest levels in nearly 50 years, Fed policymakers remain worried about excessively low inflation, a view that helps explain the recent decision to put interest-rate hikes on hold.

Traditionally, economists have found that when labor markets run hot, eventually inflation will as well but new research from in and outside the Fed has suggested that relationship may have weakened.

The yield on the 10-year note was 3.8 basis points lower, last at 2.650 percent. The two-year note was down 4 basis points at 2.489 percent and the 30-year bond yield was down 3.1 basis points at 3.015 percent.