The Obama administration rushed to restate its commitment to a stronger presence in Asia after a senior defence official reportedly said that budget cuts meant the so-called "pivot" to the region could not happen.
A senior Democratic senator voiced concern at a congressional hearing on Tuesday over the comments by Assistant Secretary of Defence for Acquisition Katrina McFarland.
According to Defense News, McFarland told a defence industry conference: "Right now, the pivot is being looked at again, because candidly it can't happen."
McFarland later issued a clarification, saying that the shift in focus to the region required difficult budget decisions and adaptation but that the "rebalance to Asia can and will continue".
The administration has made increased engagement in Asia a plank of its foreign policy as the US winds down its military involvement in Afghanistan and contends with a rising China. The US has begun a new deployment of troops in Australia and plans to shift more of its naval forces to the region.
Budget pressures have raised doubts about America's capacity to follow through on the policy.
The Pentagon on Tuesday unveiled a proposed 2015 defence budget, aiming for a smaller, more modern force, rather than a larger one less prepared for combat. Some in Congress see that as an approach that weakens US capabilities in a period of growing uncertainty in Europe and Asia.
Senator Ben Cardin voiced concern about McFarland's comments at a hearing of the panel he chairs that oversees US policy toward Asia.
David Helvey, a senior defence official for East Asia, responded that the 2015 budget would enable the US to strengthen its posture and presence "and ensure the US preserves its status as the pre-eminent military power in the region".