Federal Reserve Vice Chair for Supervision Michael Barr outlined the changes he and other regulators would like to see to the capital reform plan, including largely excluding banks with less than $250 billion of assets.

Federal Reserve Gov. Christopher Waller said the central bank should lower its target interest rate now and execute a series of cuts in months ahead.

"Fed watchers will be parsing Powell's comments for signs that a 50bp rate cut is on the table for September," noted Lauren Saidel-Baker, an economist with ITR Economics. "However, the notoriously tight-lipped chair is unlikely to confirm this, making a 25bp cut the most likely outcome."

The number of leveraged positions in Treasury futures has risen to an all-time high ahead of the central bank's annual economic symposium in Jackson Hole, Wyoming.

The figures, to be published Wednesday by the Bureau of Labor Statistics, will probably show the consumer price index, and a "core" gauge excluding food and energy, both advanced 0.2% in July.

Many on Wall Street agree that an abrupt end to quantitative tightening, or QT, is unlikely, with policymakers signaling its rolloff of Treasury holdings will finish by year-end.

Policymakers also made several adjustments to the language of a statement released after their two-day meeting in Washington, signaling they are closer to reducing borrowing costs.

Wagers on aggressive easing by the Fed had been rising in recent days amid debate over whether the central bank should act when it meets next week.

Yields on policy-sensitive two-year Treasuries slid three basis points on Wednesday, while those on 10-year bonds were up by about the same amount.

Yields across maturities rose by three to five basis points as volumes picked up in midday Monday trading in New York.