The US Ambassador to the United Nations Nikki Haley said on Tuesday Iran must be held responsible for "its missile launches, support for terrorism, disregard for human rights, and violations of UN Security Council resolutions,” Reuters reported. 

Haley was responding to Iranian President Hassan Rouhani, who said earlier on Tuesday that Iran could abandon its nuclear agreement with world powers "within hours" if the United States imposes any more new sanctions.

"Iran cannot be allowed to use the nuclear deal to hold the world hostage ... The nuclear deal must not become 'too big to fail'," Haley said in a statement, adding that new US sanctions were unrelated to the Iran nuclear deal.

Haley will travel to Vienna next week to discuss Iran's nuclear activities with UN atomic watchdog officials as part of Washington's review of Tehran's compliance with a 2015 nuclear deal, reported Reuters. 

On Tuesday, Rouhani told a session of parliament broadcast live on state television that: "If America wants to go back to the experience (of imposing sanctions), Iran would certainly return in a short time - not a week or a month but within hours - to conditions more advanced than before the start of negotiations.”

The new sanctions breach the agreement it reached in 2015 with the United States, Russia, China and three European powers in which it agreed to curb its nuclear work in return for the lifting of most sanctions, Iran said.

This comes while the US Treasury imposed sanctions on six Iranian firms in late July for their role in the development of a ballistic missile program after Tehran launched a rocket capable of putting a satellite into orbit.

In early August, US President Donald Trump signed into law new sanctions on Iran, Russia and North Korea passed by the US Congress. The sanctions in that bill also target Iran's missile programs as well as human rights abuses, reported Reuters.