U.S. government debt yields fell on Thursday as investors monitored trade deliberations between the U.S. and China and awaited updates from Washington on the impeachment inquiry into President Donald Trump.

The yield on the benchmark 10-year Treasury note was down at around 1.687%, while the yield on the 30-year Treasury bond was down at 2.129%.

Modest optimism over U.S.-China trade relations lingered on Thursday after Trump said in the prior session that a trade deal between the U.S. and China could arrive sooner-than-expected. Trump's comments on Wednesday from the United Nations sent both equities and yields higher as the more positive outlook sent traders toward riskier assets.

Bloomberg News also reported China is expected to increase its U.S. soybeans purchases during trade talks next month. Both countries have engaged in a tit-for-tat tariff war since 2018 and imposed taxes on billions of dollars' worth of each other's imports.

Yields also rose on Wednesday after Trump released a memo of a controversial phone call with Ukrainian President Volodymyr Zelensky, in which Trump encouraged his counterpart to "look into" former Vice President Joe Biden and his son, Hunter.

Some market participants viewed the memo as less damaging than initially feared, but investors stateside will continue to monitor ongoing developments in the saga as Democrats in the U.S. House of Representatives pursue an impeachment inquiry against the president.

Lawmakers are also reviewing the whistleblower complaint which prompted the memo's release, and reportedly includes concerns over how the White House handled records of the conversation, according to the New York Times.