6-K

UNITED STATES

SECURITIES AND EXCHANGECOMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATEISSUER

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

UNDER THE SECURITIES EXCHANGEACT OF 1934

For the month of May, 2026

Commission File Number001-15106

PETRÓLEO BRASILEIROS.A. - PETROBRAS

(Exact name of registrant as specified in its charter)

Brazilian Petroleum Corporation- 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

PETROBRAS ANNOUNCES REDEMPTION OF 7.375%GLOBAL NOTES DUE 2027

RIO DE JANEIRO, BRAZIL – May 28, 2026 – Petróleo Brasileiro S.A. – Petrobras (“Petrobras”) (NYSE: PBR) announces that its wholly-owned subsidiary Petrobras Global Finance B.V. (“PGF”) has delivered notices of redemption to the holders of the outstanding 7.375% Global Notes due 2027 (the “Notes”).

The redemption date for the Notes will be June 26, 2026 (the “Redemption Date”).

The redemption price for the Notes will be the greater of (A) 100% of the principal amount of such Notes and (B) the sum of the present values of the remaining scheduled payments of principal and interest thereon (exclusive of interest accrued to the Redemption Date) discounted to the Redemption Date on a semiannual basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate plus 50 basis points (the “Make-Whole Amount”), plus in the case of each of clause (A) and (B) above, accrued interest on the principal amount of such Notes from January 17, 2026 to (but not including) the Redemption Date. The Make-Whole Amount will be determined and communicated to holders of the Notes on the third Business Day preceding the Redemption Date.

Payment on the Notes will be made prior to 3:00 pm New York City time, on the business day preceding the Redemption Date, by credit to the account of The Bank of New York Mellon, the trustee for the Notes (the “Trustee”), as paying agent for the Notes. The Trustee will cause funds to be paid to The Depositary Trust Company for further payment to its participants.

On the Redemption Date, the Make-Whole Amount, plus accrued interest, will become due and payable. Interest on the Notes will cease to accrue on and after the Redemption Date. Upon the redemption, the Notes and the related guaranty by Petrobras will be cancelled and any obligation thereunder extinguished.

PGF intends to fund the amounts necessary to redeem the Notes with available cash on hand.

For more information or if you have any questions regarding the redemption, please contact Petrobras’s investor relations department at [email protected].

Forward-Looking Statements

This announcement contains forward-looking statements. Forward-looking statements are information of a non-historical nature or which relate to future events and are subject to risks and uncertainties. No assurance can be given that the transactions described herein will be consummated or as to the ultimate terms of any such transactions. Petrobras undertakes no obligation to publicly update or revise any forward-looking statements, whether as a result of new information or future events or for any other reason.

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: May 28, 2026