Former U.S. Secretary of State, John Kerry has cautioned the US Senate against putting new sanctions on Iran.

U.S. senators from both major political parties introduced legislation on March 23 to tighten sanctions on Iran over its ballistic missile launches and other non-nuclear military activities.

The bill would make sanctions mandatory for anyone involved with Iran's ballistic missile program. And it would apply sanctions to the Islamic Revolutionary Guard Corps (IRGC) while putting into law sanctions already imposed by the executive branch on individuals tied to Iranian support for alleged terrorism.

The draft bill is scheduled to be discussed on Thursday, May 25.

At this juncture, John Kerry has weighed in, sending tweets, and expressing his concern that new sanctions might jeopardize the nuclear deal he helped negotiate with in Iran.

​The former U.S. Secretary of State has also brought up the re-election of Iranian President, Hassan Rouhani and in another tweet, has said that at this point it is not a good time to put new sanctions on Iran.

Kerry in his tweets advises his former colleagues at the Senate that there are other tools available to influence Iran's behavior, before sanctions might become necessary.

At the time when the bill was introduced, Senator Robert Menendez had said that the legislation would be crafted in a way, as not to harm the nuclear agreement.

But Iran insists that any new sanctions break the "spirit" if not the letter of the nuclear deal signed between Iran and the five permanent members of the UN Security Council, plus Germany.