Amid indications that the administration of U.S. President Donald Trump may be ready to walk away from a 2015 deal aimed at curbing Iran's nuclear activities, a senior Iranian official says that Tehran is "fully prepared" for that eventuality, but he warned that its collapse could jeopardize regional stability.

"It's up to the U.S. government and Mr. Trump. If he feels that the Middle East will be a better place without (the nuclear deal), then he can try it," Deputy Foreign Minister Abbas Araghchi, Iran's chief nuclear negotiator, told Kyodo News in an interview Wednesday in Vienna.

Speaking a day after a meeting in Vienna of the Joint Commission of the Joint Comprehensive Plan of Action, as the landmark deal is formally called, Araghchi said his ministry and the Iran Atomic Energy Organization already have instructions on how to react if the U.S. government pulls out.

His remarks came just days after U.S. media reports that Trump, irked at the U.S. Congress for not implementing new nuclear sanctions against Iran, will likely pull the United States out of the deal entirely when it comes up for recertification on Jan. 13, under a law that requires him to waive such sanctions regularly.

In October, he refused to recertify it, accusing Iran of violating the spirit of the agreement, alleging its support for terrorism across Middle East and vowing never to allow it to acquire nuclear weapons.

Under the painstakingly negotiated agreement that Iran signed in July 2015 with United States, Britain, France, Germany, China and Russia, as well as the European Union, Tehran agreed to curb its nuclear activities such as uranium enrichment in return for the lifting of crippling economic and financial sanctions.

Trump has repeatedly called the deal signed during the preceding administration an "embarrassment." While campaigning for the presidency, he vowed to scrap it if elected -- though other parties dispute his authority to do so unilaterally.

Since taking office in January, however, Trump has suggested it could be renegotiated to include limits on Iran's missile capabilities.

"The nuclear deal is not renegotiable and also it's not possible to open and add anything else to it," Araghchi said, while noting that the deal was unanimously endorsed by the U.N. Security Council and that the International Atomic Energy Agency has repeatedly confirmed Iran's compliance with its obligations.

Regarding ongoing back-and-forth between Trump and the U.S. Congress over the deal and over Trump's push to ramp up sanctions on Iran, the deputy foreign minister said, "This has nothing to do with us. What is important for us is U.S. full compliance."

Araghchi said the U.S. delegation assured the Joint Commission that the United States remains committed to fulfilling its obligations under the deal, even as it has imposed sanctions against Iran since implementation began and is mulling even more.

He accused Washington of also violating the spirit of the deal by creating an atmosphere of "confusion" and "uncertainty" around it, which has rattled foreign companies operating in Iran and frightened off potential investors.

The commission that met in Vienna is responsible for overseeing the deal's implementation, including the sanctions-lifting process, and dealing with complaints raised by the parties.

It was agreed Wednesday to hold the next meeting in April, Araghchi said.

The European Union has rebuffed Trump's call for the deal, which culminated 12 years of EU-facilitated diplomacy, to be renegotiated, insisting it is "working."

EU foreign ministers warned last October that its collapse could have serious security implications, while also undermining efforts to get North Korea to freeze its nuclear and missile development programs.