The Treasury Secretary already has this power in limited quantities. Under existing law, the regulator, in consultation with the Federal Reserve Chair, Secretary of State, federal regulators and other agencies can impose these restrictions on transactions. However, a public rulemaking notice must be issued alongside the restriction, and the restriction will lift after 120 days unless the Treasury Department implements a rule continuing the block after the comment period.
Source: https://www.coindesk.com/policy/2022/01/28/house-bill-could-let-treasury-secretary-block-international-crypto-transactions/