The benchmark 30-year yield jumped to 2.12% in early Tokyo trade, extending its advance from last month's low of 1.81%
Bonds from the two countries are already leading gains in emerging Asia this quarter, offering 3%-5% returns to dollar-based investors
Holdings of the SPDR Gold Trust fell 0.3 per cent to 990.32 on Monday
The euro was down 0.1% versus the dollar at $1.1686.
The yen was little changed at 110.985 per dollar, not far from Monday's low of 111.07, a level not seen since July 5.
The calls are the latest sign of mounting pressure on the US government to avert a potential crisis if it's no longer able to borrow money to pay its bills
The staffing shortfall has left Yellen's team frustrated with over-stretched portfolios, hurting morale as work to develop and enact policies becomes more difficult
Yellen has campaigned for congressional action and has warned that the Treasury would probably reach the borrowing limit sometime next month.
Both indices added nearly 9 per cent each in August, their best monthly showing since November
Afghanistan is in dire need of funds, but nothing of consequence happens at lending institutions like the IMF without US approval.
The amount of cash investors are parking at a major Federal Reserve facility surged above $1 trillion once again amid an overabundance of US dollars
The dollar also scaled a four-month high versus the euro as investors looked ahead to U.S. inflation numbers on Wednesday
The dollar also scaled a four-month high versus the euro
Yellen urged agency heads at the July 19 meeting to "act quickly" to ensure stablecoins face appropriate rules
Asian shares and US Treasury yields rose on Wednesday, clawing back some of the week's losses as investors reassessed economic worries
Spot gold was up 0.1% at $1,812.83 per ounce, as of 0243 GMT, after falling 1% in the previous session
Questions remain over US admin's ability to get Congress to ratify changes
Treasury yields extended their rise on Friday while the three major US stock indexes rallied to record closing highs, as markets relaxed a bit from fears of a slowing pace of economic recovery
Gold edged higher on Friday and was set for its third straight weekly gain, as concerns over the fast-spreading Delta variant and a drop in US Treasury yields lifted the safe-haven metal's demand
The fresh burst in pessimism continued a pattern set earlier in the week