SAN FRANCISCO ¡ª T he next iPhone comes out June 24 and will have a higher-resolution screen, longer battery life and thinner design.

CEO Steve Jobs opened Apple Inc.¡¯s annual conference for software developers Monday by demonstrating the iPhone 4, which will cost $199 or $299 in the United States with a two-year AT&T contract, depending on the capacity.

Preorders will begin on June 15 in Japan. There is no official word yet from Softbank Mobile, Japan¡¯s exclusive carrier of the iPhone, on pricing and plans.