Correction: An earlier version of this article incorrectly referred to Tel Aviv as the capital of Israel. Israel designated Jerusalem as its capital in 1950, although many countries maintain embassies and other diplomatic missions in Tel Aviv because of the Palestinians’ competing claim on Jerusalem as their capital. This version has been corrected.

President Obama delivered his annual message to the Iranian people on Tuesday, using a far more confrontational tone than usual to say that he will seek ways to break through the “electronic curtain” that Tehran has thrown over the Internet and other forms of communication.

“I want the Iranian people to know that America seeks a dialogue to hear your views and understand your aspirations,” he said in his message to mark Nowruz, the Persian new year.

“The United States will continue to draw attention to the electronic curtain that is cutting the Iranian people off from the world,” Obama said. “And we hope that others will join us in advancing a basic freedom for the Iranian people: the freedom to connect with one another and with their fellow human beings.”

Since taking office, Obama has used his Nowruz message to speak directly to Iranians to try to find common ground between the United States and Iran.

But his remarks this year reflect the building pressure on Iran and the rising fear of an imminent military confrontation between Israel and the Islamic republic over Iran’s nuclear enrichment program. In his first message, three years ago, Obama sought “the promise of a new beginning” with Tehran.

This year’s message coincided with efforts by the administration to sharpen the impact of economic sanctions aimed at Iran’s rulers. The State Department said Tuesday that it will grant exemptions from U.S. economic penalties to 11 countries that have voluntarily reduced their reliance on Iranian oil.

Those nations — Japan and 10 European Union members — are traditional consumers of Iranian petroleum. All were potentially subject to new, congressionally mandated economic sanctions that penalize any foreign banks involved in oil transactions with the Central Bank of Iran. European countries have approved a boycott of Iranian oil imports beginning July 1, and Japan has unilaterally agreed to reduce Iranian oil purchases by up to 22 percent.

U.S. officials are negotiating with 12 other customers of Iran, including China, India and South Korea, to encourage cutbacks in Iranian oil purchases before June 28, when the U.S. sanctions are set to take effect.

Secretary of State Hillary Rodham Clinton praised the 11 nations for showing “solidarity and their commitment to holding Iran accountable.”

Obama’s more aggressive message this year reflects the increasing concern in the United States, Israel and other countries about Iran’s enrichment program, which Israel believes will be used to produce a nuclear weapon.

In a meeting with Israeli Prime Minister Benjamin Netanyahu this month, Obama argued against a military strike until the full set of economic sanctions takes effect against Iran this summer, a squeeze the president hopes will persuade Iran’s Shiite Muslim leadership to give up the enrichment program.

But Obama, facing a difficult reelection campaign this year that would be complicated by a regional war in the oil-rich Middle East, has declared that the “window is closing” for a diplomatic solution.

Administration officials have said a goal of the sanctions is to turn the Iranian public against the government, perhaps forcing it to give up its nuclear program.

As he has in the past, Obama spoke to Iranians through his videotaped message. His words were translated into Arabic and Farsi.

He suggested that Tehran must do more to protect Iranians’ rights at a time when much of the Arab Middle East is engaged in democratic uprisings. He noted pointedly that “over the last year, we have learned once more that suppressing ideas never succeeds in making them go away.”

“Like people everywhere, they have the universal right to think and speak for themselves,” he said of Iranians, whom he called “heirs to a great and ancient civilization.” “The Iranian government has a responsibility to respect these rights, just as it has the responsibility to meet its obligations with regard to its nuclear program.”

Obama also said “there is no reason for the United States and Iran to be divided from one another.”

He noted that the Iranian film “A Separation” won the Academy Award this year for best foreign film and that “from Facebook to Twitter — from cellphones to the Internet — our people use the same tools to talk to one another and to enrich our lives.”

He added: “Let me say again that if the Iranian government pursues a responsible path, it will be welcomed once more among the community of nations, and the Iranian people will have greater opportunities to prosper.”

Staff writer Joby Warrick contributed to this report.