US Treasurys boosted by 'safe haven' bid

U.S. Treasury bonds and notes rose across the yield curve on Wednesday, as worrying news out of North Korea piqued geopolitical concerns and spurred demand for so-called "safe haven" assets.

Benchmark 10-year U.S. Treasury notes yielded 2.1940 percent, down from a close of 2.250 percent. (Bond yields move inversely to prices: CNBC Explains.)

US 10-YR
US 30-YR

Thirty-year bonds yielded 2.9545 percent on Wednesday, having closed at 3.011 percent. Yields on two-year Treasury notes touched a fresh two-week low of 0.988 percent following the release of minutes from the December Federal Reserve meeting.

However, as investors digested the minutes, Treasury prices pared gains slightly.

Other "safe haven" assets like German bunds and gold prices also rose.

This came after North Korea announced that it had tested a hydrogen bomb overnight. This followed reports of a 5.1-magnitude earthquake near a nuclear-testing site in the country. North Korea has said that it will not relinquish its nuclear capabilities unless the U.S. drops its hostile foreign policy.

Increased tensions between Saudi Arabia and Iran are also in focus after the former cut diplomatic ties with the latter. On Tuesday, the Saudi foreign minister stoked the dispute, telling CNBC that "Iranians have got away with murder, literally, for more than 30 years."

Meanwhile, Brent crude and U.S. light crude futures for February delivery traded near $34 per barrel early on Wednesday, sharply down on the day.

On the data front, the December ADP employment report showed private payrolls jumped 257,000, well above the expected 192,000 increase. Meanwhile, the Commerce Department said the U.S. trade deficit narrowed by 5 percent to $42.4 billion in November.

The ISM non-manufacturing index for December hit 55.3, slightly below consensus estimates.

In addition, the minutes from December's interest rate-raising meeting of the Federal Reserve showed some policymakers showed concerns about inflation lingering at dangerously low levels. Some members also said their decision to hike was a "close call."