U.S. Republican senators plan to introduce legislation to impose further sanctions on Iran, accusing it of violating U.N. Security Council resolutions by testing ballistic missiles and acting to “destabilise” the Middle East, a U.S. senator said Sunday.

“I think it is now time for the Congress to take Iran on directly in terms of what they’ve done outside the nuclear program,” Senator Lindsey Graham, a member of the Senate Armed Services Committee, told the Munich Security Conference.

Graham said he and other Republicans would introduce measures to hold Iran accountable for its actions.

Tensions between Tehran and Washington have risen since an Iranian ballistic missile test that prompted U.S. President Donald Trump’s administration to impose sanctions on individuals and entities linked to the country’s Revolutionary Guards.

“Iran is a bad actor in the greatest sense of the word when it comes to the region. To Iran, I say, if you want us to treat you differently then stop building missiles, test-firing them in defiance of U.N. resolution and writing ‘Death to Israel’ on the missile. That’s a mixed message,” Graham said.

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