SAN FRANCISCO — 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.