The bill, introduced by Senator Kelly Ayotte is a reflection of longstanding exasperation among Republican lawmakers who've complained that President Barack Obama has failed to properly punish Tehran for repeatedly defying a UN ballistic missile test ban.
Ayotte and other Republicans said senior US military officials are in favor of tougher sanctions. Both Defense Secretary Ash Carter and Army General Joseph Votel, Obama's choice to be the next US commander for the Middle East, have told the Senate Armed Services Committee in the last week that harder hitting sanctions are necessary.
But Iran's UN Mission said in a statement that the country "has never sought to acquire nuclear weapons and never will in the future." It said the missile tests "were part of ongoing efforts of its armed forces to strengthen its legitimate defense capabilities ... Against security threats."
The administration in January announced sanctions against Tehran for missile firings in late 2015, but Republicans called those measures tepid and weak.
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"Tough words alone will not deter the world's worst state sponsor of terrorism from continuing to develop its ballistic missile program," Ayotte said.
The legislation requires new sanctions against persons who knowingly aid Iran's missile program and against entities controlled or owned in part by Iran's primary ballistic missile organizations.
The bill also would mandate a broad reach by requiring the president to issue sanctions on entire sectors of Iran's economy found to be directly or indirectly supporting Iran's missile program.