The Congressional Budget Office said Friday that President Donald Trump’s tariff increases would trim federal budget deficits by an estimated $4 trillion between 2025 and 2035 if the levies remain in place. The non-partisan agency projects that higher duties will shrink primary deficits by $3.3 trillion and lower interest costs on federal debt by another $700 billion over the decade. CBO Director Phillip Swagel wrote in an update that the effective tariff rate on U.S. imports has risen about 18 percentage points compared with 2024 trade flows. The agency now expects customs duties to reach roughly $200 billion in the current fiscal year, up sharply from the $80 billion it forecast in January after Treasury data showed $136 billion collected through July. The new outlook marks a sizeable revision from June, when the CBO estimated a $2.5 trillion cut in primary deficits and a $500 billion reduction in interest outlays. While the watchdog cautioned that ongoing negotiations and legal challenges could alter tariff rates, it said the added revenue would help offset deficit increases tied to the Republican tax-and-spending legislation enacted earlier this year.