US Secretary of State Condoleezza Rice began talks with European and Russian officials on Thursday to urge greater international pressure on Iran to halt uranium enrichment and answer questions about its nuclear programs. Days after a new US intelligence estimate contradicted years of assertions that Iran is secretly pursuing atomic weapons, Rice was stressing with NATO allies and Russia the US case for continued isolation of the Iranian regime. Rice said she would argue during the two days of meetings for more pressure. It is her first face-to-face sessions with world powers now considering new UN sanctions on Iran over its nuclear program since the National Intelligence Estimate was released on Monday. "I don't see that the NIE changes the course that we're on," Rice told reporters aboard her plane as she flew to Belgium for a conference of NATO foreign ministers and talks between the alliance and Russia, which, along with China, has been particularly resistant to new sanctions.