Heavier US sanctions, aimed at Iran's oil sector, are due in November.
European companies will be protected from the impact of new sanctions imposed by the United States on Iran, Britain has said.
The United States has reimposed economic sanctions on Iran that were originally put in place to pressure the country to limit its nuclear program and later lifted under a 2015 global agreement.
Iran accused the United States of reneging on the nuclear agreement, signed by the Obama administration, and of causing recent Iranian economic unrest. European allies say they "deeply regret" the US action.
As of midnight, harsh sanctions on Iran have kicked in as part of the administration's strategy to keep Tehran from achieving its goal of building a nuclear bomb. The sanctions follow the Trump administration's withdrawal from the 2015 deal known as the Joint Comprehensive Plan of Action (JCPOA). "I am asking for WORLD PEACE, nothing less!" he tweeted.
"It also forbids European Union persons from complying with those [US] sanctions unless exceptionally authorised to do so by the commission", said spokeswoman Mina Andreeva.
In a statement on Monday just hours before the sanctions went back into effect, Trump said: "The Iranian regime faces a choice".
With US sanctions set to return against Iran on Tuesday, Zarif acknowledged there were hard times ahead.
"We are always in favor of diplomacy and talks..."
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College Lake is a manmade lake, built in the early 1930s by the Virginia Department of Highways as part of the development of U.S. A flash-flood watch was in effect through late Friday morning in Lynchburg, with 1 to 3 more inches of rain expected.
They were previously relaxed under the 2015 Iran nuclear deal.
"Talk to anyone, anywhere in the world and they will tell you that (Israeli Prime Minister Benjamin) Netanyahu, (US President Donald) Trump and (Saudi Crown Prince Mohammed) bin Salman are isolated, not Iran", he said.
The official said the United States expects Iran will blame it for any new hardships, saying, "They've been doing it for nearly 40 years".
"They've got to behave like a normal country".
"If you're an enemy and you stab the other person with a knife, and then you say you want negotiations, then the first thing you have to do is remove the knife", the Iranian leader said in an interview on state television.
"Most of the companies have already made up their mind, whether it's the German Siemens, the French carmaker PSA, the Danish Maersk - all these companies that have said they don't want to risk losing access to the U.S. market, they don't want to risk losing access to the financing in dollars by USA banks, and also they don't want to lose their United States shareholders".
The blocking statute applies to anyone, foreign or otherwise, who is a resident in the European Union and also does business in Iran.
Companies caught violating the sanctions could be cut off from the U.S. financial system and targeted with other punishments.