The World Jewish Congress offered cautious praise Friday for the "surprising....welcome" Rosh Hashanah greetings offered to the Jewish people by Iran's new president and foreign minister on Twitter this week, but said the Iranian leaders' welcome words of tolerance on the occasion of the Jewish new year's holiday should be followed by "concrete actions."

“The Rosh Hashanah message to 'all Jews' -- which includes those living in Israel — was a surprising gesture and a welcome change in tone compared with President Rouhani’s predecessor," World Jewish Congress President Ron Lauder said in a press statement Friday. "The comments attributed to Foreign Minister Javad Zarif on the Holocaust are also a step forward."

However, Lauder continued, "words are meaningless if they are not backed up by credible actions. Until Iran ends its support for the enemies of the Jewish state, until it stops providing support to terrorist groups targeting Israeli and Jewish targets worldwide, and a regime that is gassing thousands of its own citizens in order to remain in power, these words sound hollow."

"As the sun is about to set here in #Tehran I wish all Jews, especially Iranian Jews, a blessed Rosh Hashanah," Rouhani's official presidential English language Twitter account tweeted under his name on Wednesday, accompanied by a photo of a man praying at an Iranian synagogue.