Market relief at the Federal Reserve's unexpected Treasury buyback intervention could prove short-lived, as it fails to address deep-rooted concerns about high levels of debt and government spending, analysts said.

The move, announced late Thursday, initially sent yields on 10-year Treasuries lower and lifted stock indexes, offering temporary calm to skittish investors. However, economists caution that without broader fiscal discipline, the respite will be modest.

"This is a bandage, not a cure," said Mark Zandi, chief economist at Moody's Analytics. "Until Congress addresses the trajectory of federal debt, which now exceeds $34 trillion, we'll keep seeing volatility in fixed-income markets."

Investors are also watching the European Central Bank closely, as it signals potential rate cuts amid slowing growth. Meanwhile, the Treasury Department indicated it may accelerate issuance of longer-dated bonds to fund rising deficits, potentially offsetting demand from any Fed purchase program.

Trading desks expect range-bound activity in the coming weeks, with yield swings likely tied more to fiscal headlines than monetary gestures.