Iran's supreme leader said Friday that world powers had been persuaded they could not block Iran's nuclear progress -- making no mention of a warm new-year's message sent by President Obama to his country, Reuters reported.

Neither Ayatollah Ali Khamenei nor Iranian President Mahmoud Ahmadinejad noted Obama's attempt to make a "new beginning" with their country in recorded messages they issued to mark the Iranian New Year.

Obama released his video Friday to coincide with the Iranian festival of Nowruz, which marks the arrival of spring. In the video, Obama said the U.S. is prepared to end the strained relations if Tehran tones down its combative rhetoric.

"This process will not be advanced by threats. We seek instead engagement that is honest and grounded in mutual respect," Obama said.

A press adviser to Iran's president downplayed the video, saying "minor changes will not end the differences."

Ali Akbar Javanfekr told the Iranian state-run English-language Press TV satellite station that Iran will never forget U.S. meddling in Tehran's affairs. The two countries broke off relations after the 1979 Islamic revolution.

Ahmadinejad has said Iran would welcome talks with the U.S. -- but only if there was mutual respect. Iranian officials have said that means the U.S. needs to stop accusing Iran of seeking to build nuclear weapons and supporting terrorism, charges Tehran has denied.

It wasn't clear how many Iranians were able to see the video, which was not aired on state television in Iran on Friday. It was likely shown on Farsi-language TV stations beamed in from outside of the country, but many Iranians don't watch television in the first days of long Nowruz holiday that is normally filled with family gatherings or vacations away from home.

The Associated Press contributed to this report.