Japan's ​Nikkei share average closed at a ​record high for a third straight session on Wednesday, ​ending just shy of the 70,000 mark, on easing concerns over the Middle East conflict and sustained buying in AI-related shares ahead of the U.S. Federal Reserve's policy decision.The Nikkei ‌rose 0.7% to ⁠close ⁠at 69,902.25 after touching an intraday high of 70,125.75. The broader Topix climbed 0.6% to 4,013.23.Details ​of a U.S.-Iran interim deal to end the conflict are emerging, with President Donald ​Trump saying it would rule out a nuclear weapon for Tehran and a U.S. official saying it would allow Iran to sell oil once signed.Oil ​prices eased, extending the previous session's declines as ⁠investors assessed the ‌U.S.-Iran peace deal."As concerns over geopolitical risk continue to recede from yesterday, the market still seems to be seeing some ⁠buying driven by expectations for expanding AI demand, particularly in certain pockets of the market such as high-priced semiconductor shares and other AI-related stocks," said Maki Sawada, a strategist at Nomura Securities.Market breadth remained strong, with 137 stocks advancing against 85 decliners in the Nikkei.AI-related shares performed strongly overall, with chip inspection equipment maker Lasertec jumping 13.2% to close at a record high. Electronic components maker Murata Manufacturing rose 3.2%, ‌while industrial robots maker Yaskawa Electric advanced 2.9%.The biggest percentage decliners were life insurance group T&D Holdings, which fell 3.2%, ​followed by tech investment ​conglomerate SoftBank Group, ⁠down 3.1%, and medical endoscopes and optics company Olympus, which lost 3%.The Nikkei briefly crossed the 70,000 mark for the first time on Tuesday after the Bank ​of Japan raised interest rates to 1.00%, as widely expected.Investors will closely watch new Fed Chair Kevin Warsh's comments on inflation, unemployment and the economic outlook at his first post-Federal Open Market Committee press conference later in the day.The Fed is widely expected to keep interest rates steady.