European stock markets opened with mixed performance on Thursday as a fragile cease-fire agreement between the United States and Iran showed signs of strain. Shortly after the opening bell, the pan-European Stoxx 600 index declined by 0.2%, with major regional exchanges and sector indices showing divergent trends. The UK's FTSE 100 index opened 0.2% higher, while France's CAC 40 dropped 0.3% and Germany's DAX fell 0.6% at the start of trading.

Late on Wednesday, Iranian Parliament Speaker Mohammad Bagher Ghalibaf accused the United States of violating the cease-fire agreement less than 24 hours after it was reached. Ghalibaf cited ongoing Israeli strikes in Lebanon, the intrusion of a drone into Iranian airspace, and the U.S. denial of the Islamic Republic's right to uranium enrichment as evidence of American non-compliance. U.S. President Donald Trump stated on Wednesday that American forces would remain deployed in and around Iran until the country fully complies with what he termed a "real agreement," warning that any violation would trigger an unprecedented large-scale military response.

The dispute weighed on Asian markets, where shares broadly declined. South Korea's KOSPI index fell 1.53%, and the KOSDAQ small-cap index dropped 1.38%. In Japan, the Nikkei 225 declined 0.77%, while the Topix index slipped 0.78%. Thursday's trading in Europe followed a particularly strong performance the previous day, when the Stoxx 600 closed 3.7% higher. Among the top gainers on Wednesday were Antofagasta, Lufthansa, and easyJet, each rising around 10%.