"It becomes more difficult to undo something that's working than undo something that isn't working," Obama said on Monday, citing the success of the Iran pact, also known as the Joint Comprehensive Plan of Action (JCPOA), and the accomplishment of getting almost 200 nations to ratify the Paris Agreement on climate change climate, CNN reported.
Obama said that Trump would find it hard to tear up the deal, particularly because Iran has complied with the deal over its first year.
"For us to pull out would require us to start sanctioning those other countries that were still abiding by the deal because from their perspective they were still abiding" by the deal, Obama said.
In similar remarks on Sunday, the European Union's Diplomatic Chief Federica Mogherini said the agreement has been reflected in a UN Security Council resolution and cannot be dismissed by one government.
Iran and the Group 5+1 (Russia, China, the US, Britain, France and Germany), reached the comprehensive nuclear deal, known as the Joint Comprehensive Plan of Action (JCPOA), in July 2015 and implemented it in January 2016.
In a speech to the pro-Israeli lobby group AIPAC (American Israel Public Affairs Committee) in March, Trump declared that his "number-one priority” would be to "dismantle the disastrous deal with Iran."
After Trump's winning the election, Iran’s Foreign Minister Mohammad Javad Zarif said that Iran expects the new US administration respect the nuclear deal.