TEHRAN — Iran warned on Friday that it was prepared to abandon its fragile ceasefire with the United States, accusing Washington of violating the truce terms and threatening renewed military action. Oil prices rose in early trading in response.

The ceasefire, brokered after weeks of confrontation between Iranian and American forces, has grown increasingly tenuous. Iran's Foreign Ministry said the truce could not hold if American provocations continued, while the White House maintained its commitment to de-escalation.

Brent crude rose as analysts at ING and Goldman Sachs warned that any breakdown could disrupt shipments through the Strait of Hormuz, through which roughly a fifth of the world's oil passes. Traders cited fears of supply shocks and higher fuel prices for consumers.

The standoff has drawn concern across European and Gulf capitals, where governments fear a wider regional conflict. The European Union called for restraint on both sides and urged the parties to preserve the ceasefire framework.

Iran's Supreme National Security Council was expected to convene to weigh its options, according to Iranian state media. Diplomats in Oman and Qatar sought to keep back-channel talks alive to prevent a full collapse of the agreement.