BEIRUT (Reuters) - Supreme Leader Ayatollah Ali Khamenei, the highest authority in Iran, said the country has nothing to be concerned about, a report on his official website said on Wednesday in an apparent reference to the imposition of strict U.S. sanctions this week.

FILE PHOTO: Iran's Supreme Leader Ayatollah Ali Khamenei speaks during Friday prayers in Tehran September 14, 2007. REUTERS/Morteza Nikoubazl//File Photo

The sanctions imposed on Tehran this week have already led banks and many companies around the world to scale back dealings with Iran. Companies doing business with Iran will be barred from the United States, President Donald Trump said on Tuesday.

“With regard to our situation do not be worried at all. Nobody can do anything,” Khamenei said recently, the website reported.

“They can be sure. There is no doubt about this,” Khamenei was quoted as saying in comments that appeared only a day after the new U.S. sanctions took effect.

U.S. officials have said in recent weeks that they aim to pressure countries to stop buying oil from Iran in a bid to force Tehran to halt its nuclear and missile programs and involvement in regional conflicts in Syria and Iraq.

“These are the most biting sanctions ever imposed,” Trump tweeted on Tuesday.

Separately, Iranian Foreign Minister Mohammad Javad Zarif said Wednesday that a U.S. plan to reduce Iran’s oil exports to zero will not succeed, according to the Iran newspaper.

“If the Americans want to keep this simplistic and impossible idea in their minds they should also know its consequences,” Zarif told the Iran newspaper.

“They can’t think that Iran won’t export oil and others will export.”

President Hassan Rouhani hinted last month that Iran could block the Strait of Hormuz, a major oil shipping route, if the U.S. attempted to stop the Islamic Republic’s oil exports.

U.S. President Donald Trump responded by noting that Iran could face serious consequences if it threatened the United States.

“The Americans have assembled a war room against Iran,” Zarif said. “We can’t get drawn into a confrontation with America by falling into this war room trap and playing on a battlefield.”

Last month, Trump offered to meet Iran’s leaders. Zarif said that Oman and Switzerland have acted as mediators in talks with America in the past but that there are currently no direct or indirect talks being held with the United States.

Rouhani, speaking in a meeting with North Korea’s foreign minister on Wednesday, said that America cannot be trusted, according to the Islamic Republic News Agency (IRNA).

“Today, America is identified as an unreliable and untrustworthy country in the world which does not adhere to any of its obligations,” Rouhani said.