Oil closes at three-week high as hopes of US-Iran peace deal fade

By Siddharth Cavale and Robert Harvey

NEW YORK, Aug 18 (Reuters) - Oil prices settled at their highest level in more than three weeks on Tuesday after Iran said it would adopt a more offensive stance and the Strait of Hormuz would remain closed, while the United States ruled out extending a ceasefire.

Gains were limited, however, with Brent crude futures finishing up 15 cents, or 0.17%, at $91.02 a barrel, while U.S. West Texas Intermediate crude futures closed up 44 cents, or 0.52%, at $84.94 a barrel. Both contracts closed at their highest since July 24.

"To some extent, the market has muted movement to the daily headlines just due to the amount of noise since June with no real results," said Darrell Fletcher, managing director of Commodities at Bannockburn Capital Markets. 

"Covert or dark shipments slipping from the Strait of Hormuz seem to be more than the market expected ... adding to some buffering from higher prices," Fletcher said.

Saudi Aramco has resumed oil loadings from inside the strait, and is offering cargoes for loading via ship-to-ship transfers off Fujairah in the UAE, according to shipping data and trade sources.

Two Chinese shipping giants also have started collecting oil cargoes outside the Gulf, according to industry executives, tanker trackers and brokers. 

While that has eased some supply concerns, vessel traffic through the strategic waterway remains in the single digits. The tally does not include vessels passing through the strait with their transponders switched off.

PEACE DEAL HOPES DIM

Iran will keep the strait closed until the United States meets the conditions of the interim deal signed in June, top Iranian negotiator Mohammad Baqer Qalibaf said in comments published by state media on Tuesday.

Trump, who previously labeled that deal "over," said on Tuesday that talks between the United States and Iran were neither taking place nor scheduled, but the strait was open. His comments were met with a muted market reaction.

Qalibaf's comments came after a senior Iranian official told Reuters on Monday that Iran will shift to a "fully offensive" military posture as efforts have stalled toward a permanent end to the war.

Mohit Kumar, an economist at brokerage Jefferies, said the two countries are not yet at the pain points where either would want to make a deal. 

"Hence, we see further pain in the near term and upward pressure on oil prices," Kumar said.

Iran has separately been negotiating with Oman on an agreement on managing the strait and says they are close to a deal. Trump responded to those talks with a threat to bomb Oman, a longstanding U.S. security partner.

MIDDLE EAST ATTACKS CONTINUE

Yemen's Houthis launched missiles in an attack on vessels they described as a Saudi military ship and four escorts in the Red Sea, their military spokesperson, Yahya Saree, said on Telegram.

Separately, the United Kingdom Maritime Trade Operations said it received a report on Tuesday that a vessel was struck by an unknown projectile while transiting out of the strait, causing engine room damage and a crew casualty. 

Later in the day, the United Arab Emirates said it detected two ballistic missiles launched from Iran against the country. There was no immediate comment from Iran. 

Four sources told Reuters that Russia is rerouting Kazakhstan's crude oil exports from the Baltic port of Ust-Luga to the Black Sea port of Novorossiysk, freeing up capacity for more Russian oil exports from the Baltic amid heightened Black Sea security risks. 

The move would allow Russia to replace Kazakh barrels at Ust-Luga with its own crude exports, while Ukrainian drone attacks make it more difficult for Russian exporters to secure tankers for Black Sea loadings. 

(Reporting by Siddharth Cavale in New York and Robert Harvey in London, Ishaan Arora in Bengaluru and Trixie Yap in Singapore; Editing by Kirsten Donovan, Mark Potter, Will Dunham and Chris Reese)