Acting White House Budget director Russell Vought has urged the US Congress to delay the implementation of certain provisions in a ban on doing business with China’s Huawei.

Vought expressed his concerns in a letter to Vice-President Mike Pence and nine lawmakers last week, arguing that legislation restricting US government business with firms that work with Huawei does not provide enough time for suppliers to adjust.

The issue is not directly related to Huawei being placed on the Department of Commerce’s “entity list” earlier this year. Vought’s request for a two-year delay was in regards to provisions in the National Defense Authorization Act, signed into law last year. The NDAA restricts US government entities from doing business with Huawei and certain other Chinese firms.

Earlier this year, the Chinese telecommunications national champion filed a lawsuit challenging the law, arguing that it was unconstitutional.

Vought’s letter, first reported by The Wall Street Journal, warned that certain NDAA provisions risk causing a “dramatic reduction” in the number of firms that could supply the US government.

“A number of agencies have heard significant concerns from a wide range of potentially impacted stakeholders who would be affected,” the letter said.

The request did not signal a policy shift, a spokesperson for the White House Office of Management said, but rather just a realization that more time was needed to prepare.

“This is about ensuring that companies who do business with the US government or receive federal grants and loans have time to extricate themselves from doing business with Huawei and other Chinese tech companies listed in the NDAA,” the spokesman said.