PBR 6-K

UNITED STATES

SECURITIES AND EXCHANGECOMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGNPRIVATE ISSUER

PURSUANT TO RULE 13a-16OR 15d-16

UNDER THE SECURITIESEXCHANGE ACT OF 1934

For the month of September,2025

Commission File Number001-15106

PETRÓLEO BRASILEIROS.A. - PETROBRAS

(Exact name of registrant as specified in its charter)

Brazilian PetroleumCorporation - PETROBRAS

(Translation of Registrant's name into English)

Avenida Henrique Valadares,28 20241-030 - Rio de Janeiro, RJFederative Republic of Brazil

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F x Form 40-F

This report on Form 6-K is incorporated by reference in the Registration Statement on Form F-3 of Petróleo Brasileiro S.A. – Petrobras (No. 333-283981) and Petrobras Global Finance B.V. – PGF (No. 333-283981-01).

Exhibit 15.1 — Awareness Letter of KPMG Auditores Independentes.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: September 3, 2025

Exhibit 15.1

KPMG Auditores Independentes Ltda.

Rua do Passeio, 38, setor 2, 17º andar - Centro

20021-290 - Rio de Janeiro - RJ

Caixa Postal 2888 - CEP 20001-970 - Rio de Janeiro/RJ - Brasil

Telefone +55 (21) 2207-9400, Fax +55 (21) 2207-9000

www.kpmg.com.br

September 3, 2025

Petróleo Brasileiro S.A. - Petrobras

Av. Henrique Valadares, 28

20231-030 Rio de Janeiro - RJ

Petrobras Global Finance B.V.

Weena 798C, 23^rd^ floor

3014 DA Rotterdam

Rotterdam, The Netherlands

Re: Registration Statement Nos. 333-283981 and 333-283981-01 (the “Registration Statements”)

With respect to the Registration Statements of Petróleo Brasileiro S.A. – Petrobras and Petrobras Global Finance B.V., we acknowledge our awareness of the use and incorporation by reference therein of our report dated August 7, 2025 related to our review of the unaudited condensed consolidated interim financial statements of Petróleo Brasileiro S.A.

Pursuant to Rule 436 under the Securities Act of 1933 (the “Act”), such report is not considered part of a registration statement prepared or certified by an independent registered public accounting firm, or a report prepared or certified by an independent registered public accounting firm within the meaning of Sections 7 and 11 of the Act.