Treasury yields sink after Trump says he'll sell more 'highly sophisticated military equipment' to Japan and South Korea

Treasurys are surging on Tuesday as traders return to work following the Labor Day weekend that saw North Korea hold its sixth - and largest - nuclear test.

Yields were edging higher as traders began to settle into their desks on Tuesday, but dove to session lows following a tweet from President Donald Trump stating, "I am allowing Japan & South Korea to buy a substantially increased amount of highly sophisticated military equipment from the United States."

Post-tweet buying has yields down almost 6 basis points in the belly of the curve. Here's a look at the scoreboard as of 9:33 a.m. ET:

• 2-year -3.2 bps at 1.310%
• 3-year -4.1 bps at 1.418%
• 5-year -5.3 bps at 1.685%
• 7-year -5.8 bps at 1.934%
• 10-year -5.8 bps at 2.108%
• 30-year -4.9 bps at 2.728%

Thursday's bid has pushed yields across the curve to their lowest level since the week following the US election. The benchmark 10-year yield was hovering around 1.80% ahead of the election, and rallied sharply following Trump's win on speculation his policies would bring back growth and inflation to the US.

Traders continue to watch the 2-10-year spread, which is tighter by 2.5 bps at 79.4 bps. It is trading near its flattest levels since the fourth quarter of 2007. Traders watch the yield curve closely as it usually can predict a coming recession.