Iran has described last week's arrest of Huawei executive Meng Wanzhou on US orders as an act of "desperation" by Washington.
Wanzhou, the chief financial officer of the Chinese tech giant, was arrested in Canada following a US request after she was accused of violating trade sanctions against Iran.
"The Americans have become isolated in the world and are resorting to petty actions in this conflict (against Iran), such as arresting the financial chief of a big Chinese company to push ahead with their policies," Foreign Minister Mohammed Javad Zarif said at a conference with regional powers.
"This shows America's desperation more than it shows America's power."
President Hassan Rouhani, who spoke at the conference, accused the US of "economic terrorism" and undermining its own battle with militancy.
Washington has granted waivers to some countries to wind down its trade with Iran, but the arrest of Meng Wanzhou is seen as a message that it is serious about the sanctions.
