Secretary of State Condoleezza Rice and British Foreign Secretary David Miliband are stepping up warnings to Iran to come clean about its nuclear programs soon _ or face new sanctions.

The two top diplomats said Thursday that Tehran must comply with international demands to halt work that could produce atomic weapons components and should accept a package of incentives offered by major world powers to do so.

Rice and Miliband spoke ahead of the release of a new report expected to show that Iran is continuing to deny U.N. experts access to its records. Iran denies its nuclear program is weapons-related.