U.S. President Barack Obama delivered a video message on the occasion of the Persian new year. In his message, Obama said that Washington was committed to "a more helpful future" for the Iranian people.
The weekend statement comes as Washington lobbies for tighter economic sanctions for Iran as punishment for a controversial nuclear program.
"Our offer of comprehensive diplomatic contacts and dialogue stands," Obama added. "Indeed, over the course of the last year, it is the Iranian government that has chosen to isolate itself and to choose a self-defeating focus on the past over a commitment to build a better future."
Ayatollah Ali Khamenei, taking a consistent theme with the Obama administration, said Washington was speaking of peace and engagement while pursuing an opposite policy with Iran.
"The new administration and president claimed interest in just and fair relations," Iran's Press TV quoted Khamenei as saying. "They wrote letters and sent messages ... saying they are willing to normalize relations with the Islamic Republic but in practice they did the opposite."
Iran announced this year that it planned to enrich uranium to 20 percent, seen as a technological milestone in the path toward a nuclear weapon.