Irans Supreme Leader
He said on Monday in Teheran during a meeting with new Iranian legislators, that the Americans, including the government, Congress or presidential candidates, continue to make excessive demands and threats.
Khamenei said this has become imperative because the American stance and threats haven't changed.
"The enemy calculates reactions and if it senses any passivity or acquiescence from the opposing side, it increases its demands.
Under such circumstances, "We cannot remain silent when insulted by insolent enemies.
``We must to be present in the international arena in order to silence them with a strong response," he said.
Khamenei referred to Iran's "important" role in the Middle East's political direction, stating that Iran is the only obstacle preventing the triumph of Washington's strategy for the volatile Middle East region.
They were planing for a "new Middle East," a "greater Middle East," several years ago, but their plans for Iraq, Syria, Lebanon and the Palestinian territories, have failed due to Iran's defiance.
"There is a need to stand up to hegemonic policies and unmask their arrogant stance," he said.
Since Iran's nuclear deal was finalised, which is known as the Joint Comprehensive Plan of Action, and after the West along with the UN lifted nuclear sanctions off of Iran, the country has yet to reap economic gains expected from the deal.
Washington recently blacklisted several Iranian and foreign entities owing to their involvement in Iran's missile program.
These restrictions bar U.S. companies from undertaking business transactions with Iran's government and concern international companies from falling victim to U.S. punitive legislative measures if they invest in Iran.
The U.S. administration issued its annual State Department report on Saturday in which it designated the Islamic republic of Iran as a leading sponsor of global terrorism, a claim which was rejected by Iran's Foreign Ministry.
Iranian senior officials said they would assist regional countries and resistance movements facing the continued occupation of Palestinians territories by Israel as well as the spreading regional extremism.