Ayatollah Ali Khamenei dismissed Donald Trump’s warning to Iran to stop its missile tests, saying the new U.S. president had shown the “real face” of American corruption.

In his first speech since Trump’s inauguration, Iran’s supreme leader called on Iranians to respond to Trump’s “threats” on Feb. 10, the anniversary of Iran’s 1979 Islamic revolution. Trump had tried but failed to frighten Iranians, Khamenei said.

“We are thankful to (Trump) for making our life easy as he showed the real face of America,” Khamenei told a meeting of military commanders in Tehran, according to his website.

The White House has said the last week’s missile test was not a direct breach of Iran’s 2015 nuclear pact with six world powers, but that it “violates the spirit of that”.

In remarks published on Tuesday, Iranian Foreign Minister Mohammad Javad Zarif said Tehran would not agree to renegotiate its nuclear agreement.

“I believe Trump will push for renegotiation. But Iran and European countries will not accept that,” Mohammad Javad Zarif told Ettelaat newspaper. “We will have difficult days ahead.”

On the campaign trail, Trump repeatedly promised to tear up the nuclear deal. While his Secretary of State, Rex Tillerson, has not called for an outright rejection of the accord, he has suggested a “full review” of it.

The supreme leader, Iran’s top authority, also said Trump has “confirmed what we have been saying for more than 30 years about the political, economic, moral and social corruption in the U.S. ruling system.”

Trump responded to a Jan. 29 Iranian missile test by saying “Iran is playing with fire” and slapping fresh sanctions on individuals and entities, some of them linked to Iran’s elite Revolutionary Guards.

“No enemy can paralyze the Iranian nation,” Khamenei said. “(Trump) says ‘you should be afraid of me’. No! The Iranian people will respond to his words on Feb. 10 and will show their stance against such threats.”

A U.N. Security Council resolution underpinning the pact urges Iran to refrain from testing missiles designed to be able to carry nuclear warheads, but imposes no obligation.

Under the accord, Iran agreed to curb its nuclear program in exchange for relief from some U.S., European and U.N. economic sanctions. Critics of Iran said the deal emboldened Tehran to increase its involvement in wars in Arab countries, a charge Tehran denies.

President Hassan Rouhani said on Tuesday that, in contrast to Trump’s view, the nuclear deal was a “win-win” accord, and could be used as a stepping stone to defuse tension in the region.

(Reporting by Bozorgmehr Sharafedin; Writing by William Maclean; Editing by Robin Pomeroy and Raissa Kasolowsky)