Iran's President Hassan Rouhani said on Friday (October 13) that Iran will not renegotiate the nuclear deal following President Donald Trump's decision not to certify the deal.

Defying Trump, Rouhani said Tehran will double its efforts to expand the country's defence capabilities, including the country's ballistic missile programme despite the U.S. pressure to suspend it.

He added that Trump's decision to decertify the deal would isolate the United States as other signatories of the accord remained committed to it.

Trump said in an address at the White House that he would not continue to certify the multinational agreement and warned he might ultimately terminate it.

While Trump did not pull the United States out of the agreement, aimed at preventing Iran from developing a nuclear bomb, he gave the U.S. Congress 60 days to decide whether to reimpose economic sanctions on Tehran that were lifted under the pact.

That increases tension with Iran as well as putting Washington at odds with other signatories of the accord such as Britain, France, Germany, Russia, China and the European Union, who say the U.S. cannot unilaterally cancel the 2015 nuclear deal between Iran and world powers .