Lower yields reduce the opportunity cost of holding non-yielding gold, while a weaker dollar makes bullion cheaper for non-US investors. Higher interest rates would push yields up and likely boost the dollar.
Spot gold was up 1 percent at $1,249.43 an ounce at 1248 GMT, its highest in two weeks and taking its gains since a May 9 low of $1,213.81 to 3 percent.
US gold futures were 1.1 percent higher at $1,249.90 an ounce.
"Downward movement in yields and the dollar have given support to gold," ABN AMRO analyst Georgette Boele said. "And on top of this you get political uncertainty which is denting the dollar."
US President Donald Trump is under pressure to explain whether he tried to interfere with a federal investigation after reports that he asked then-FBI Director James Comey to end a probe into his former national security adviser Michael Flynn.
That follows a turbulent week after Trump fired Comey and discussed sensitive national security information with Russia's Foreign Minister.
This has led investors to question whether Trump can push through tax cuts and deregulation and fuelled demand for safe-haven assets including gold.
The dollar, which hit a 14-year high in January in anticipation of Trump's stimulus measures, has fallen to its lowest since he was elected in November and is likely to drop further, Boele said. 10-year US bond yields were at a 3-week low.
An unexpected fall in US homebuilding meanwhile added to a run of weak economic data, raising new doubts about how many times the Federal Reserve will raise interest rates this year.
Futures traders are pricing in a 71 percent chance of a June rate rise, down from around 90 percent earlier this month, according to CME's FedWatch Tool.
On the technical side, gold tested resistance at its 200-day moving average and Fibonacci retracement, both at around $1,245.
If gold can hold above that level it could rise to its long-term downtrend line at $1,287 an ounce, said technical analysts at Commerzbank.
In other precious metals, silver was 0.7 percent up at $16.94 an ounce and platinum was 0.6 percent higher at $943.50 an ounce. Palladium was down 1.5 percent at $781.65.