US Treasury Assistant Secretary for Tax Policy Ken Kies indicated this week it is unlikely that a General Explanation of the Administration's Revenue Proposals document (known colloquially as the "Green Book") will accompany the coming FY27 Budget document release. There are reports the Administration plans to release the proposed budget at the end of March or beginning of April.

Addressing a Tax Policy Summit on 10 March, the Treasury official suggested that a Green Book would only be necessary if the Administration has many new tax proposals.

Republicans this week also debated the merits of attempting a second budget reconciliation bill before the November mid-term elections that would follow up on last summer's One Big Beautiful Bill Act.

There was some discussion on the topic at the House Republican members' policy retreat at President Trump's Doral resort in Florida. Though there are lingering doubts that the narrowly divided House can pass another party-line bill, it remains of interest to GOP leaders and some members, including the Budget Committee chairmen in both the House and Senate. Time is another factor that comes into play as the focus begins to turn to the mid-term elections.

A senior Treasury official this week addressed the US position on Pillar One, as well as what to expect in terms of Pillar Two guidance from the OECD.

Recall that Pillar One proposed new nexus and profit allocation rules with the objective of assigning a greater share of taxing rights over global business income to market countries. The official suggested that a reassessment of Pillar One is required and that a constructive dialog is necessary, during which the US "should be leading and listening." She said it is important to understand why countries believe Pillar One was necessary, why they supported it and what problem it purported to solve.

Summing it up, the Treasury official said, "Let's challenge the assumptions, let's challenge whether the problem we thought we were solving for exists — is different, is bigger, is smaller."

On Pillar Two, the official was quoted as saying there are "three buckets" that need to be addressed in future OECD guidance. The first area of focus is for countries to determine if they qualify for the ultimate parent safe harbor that would shield their parent companies from the global minimum tax in the global anti-base erosion (GloBE) rules. Currently, only the US has received such a dispensation under the "side-by-side" agreement.

Another important area being worked on is simplifying the Pillar Two rules. And finally, she said guidance will come on how the US side-by-side agreement will mesh with the Pillar Two global minimum tax rules. As an example, the official was quoted as saying the global minimum tax return will specify that US companies will only file their global minimum tax return for qualified domestic minimum top-up taxes.

There were major US trade developments this week.

On 12 March, the Office of the United States Trade Representative (USTR) announced new investigations under Section 301 of the Trade Act of 1974 relating to "Acts, Policies, and Practices of Various Economies Related to the Failure to Impose and Effectively Enforce a Prohibition on the Importation of Goods Produced with Forced Labor." (A Global Tax Alert has details.)

This announcement follows the USTR's 11 March announcement initiating Section 301 investigations relating to acts, policies and practices of 16 economies relating to structural excess capacity and overproduction in manufacturing sectors. (A Global Tax Alert has details.)

The 12 March Section 301 investigations will focus on 60 economies to "determine whether acts, policies, and practices … related to the failure to impose and effectively enforce a ban on the importation of goods produced with forced labor are unreasonable or discriminatory and burden or restrict U.S. commerce."

Those jurisdictions are: Algeria, Angola, Argentina, Australia, The Bahamas, Bahrain, Bangladesh, Brazil, Cambodia, Canada, Chile, China, Colombia, Costa Rica, Dominican Republic, Ecuador, Egypt, El Salvador, European Union, Guatemala, Guyana, Honduras, Hong Kong, India, Indonesia, Iraq, Israel, Japan, Jordan, Kazakhstan, Kuwait, Libya, Malaysia, Mexico, Morocco, New Zealand, Nicaragua, Nigeria, Norway, Oman, Pakistan, Peru, Philippines, Qatar, Russia, Saudia Arabia, Singapore, South Africa, South Korea, Sri Lanka, Switzerland, Taiwan, Thailand, Trinidad and Tobago, Türkiye, United Arab Emirates, United Kingdom, Uruguay, Venezuela and Vietnam.

The newly initiated Section 301 investigations on overproduction focus on 16 global economies "that appear to exhibit structural excess capacity and production in various manufacturing sectors, such as through large or persistent trade surpluses or underutilized or unused capacity."

The jurisdictions covered by these investigations are: China, the European Union, Singapore, Switzerland, Norway, Indonesia, Malaysia, Cambodia, Thailand, Korea, Vietnam, Taiwan, Bangladesh, Mexico, Japan, and India. At least a dozen of these trading partners finalized or announced trade deals with the United States under the previous International Emergency Economic Powers Act (IEEPA) tariff regime. The USTR also provided an illustrative list of sectors that may be prone to overproduction,

The USTR generally has 12 months to complete an investigation under Section 301. The USTR has indicated, however, that it would move expeditiously in conducting new Section 301 investigations, suggesting that findings and associated reports could come as early as this summer.

Also on 12 March, the US Customs and Border Protection (CBP) submitted a declaration to the US Court of International Trade outlining how CBP is building a new, dedicated process within its Automated Commercial Environment (ACE) to administer valid refunds of tariffs imposed under IEEPA. The CBP also reported on the progress being made in its development of the Consolidated Administration and Processing of Entries (CAPE) Claim Portal, which will be used to calculate, liquidate/reliquidate and refund IEEPA-related duties through a phased rollout. In a subsequent order issued on 12 March, the CIT reported that development of the claims portal was progressing at a "satisfactory" pace. The CIT directed CBP to continue advancing the project and required that a further update on the status of the portal be submitted on 19 March 2026. (A Global Tax Alert has details.)