Trump Adamant-Not In Our Interest To Continue With It!

Chances are that the deadline of October 15 for continuation of implementation of the Iran nuclear deal will not be met, as the president will probably decertify it. As he clearly states that Iran has not lived up to the spirit of the agreement and it is not in the interest of the United Sates to continue implementing it, even if Iran has not violated any concrete obligations provided by it.
Donald Trump

If the agreement becomes decertified, the president will recommend to Congress to reimpose sanctions, either congressional or executive.
Decertification would have no automatic consequences in terms of U.S. implementation of the agreement with respect to the continued suspension of sanctions that had been waived or rescinded under the JCPOA. In order to have such an effect, decertification must be accompanied by measures to reimpose sanctions.

In the original agreement the following COMPLIANCE CERTIFICATION was signed-After the review period provided in subsection (b), the President shall, not less than every 90 calendar days —
(A) Determine whether the President is able to certify that —
(i) Iran is transparently, verifiably, and fully implementing the agreement, including all related technical or additional agreements;
(ii) Iran has not committed a material breach with respect to the agreement or, if Iran has committed a material breach, Iran has cured the material breach;
(iii) Iran has not taken any action, including covert activities, that could significantly advance its nuclear weapons program; and
(iv) suspension of sanctions related to Iran pursuant to the agreement is —
(I) appropriate and proportionate to the specific and verifiable measures taken by Iran with respect to terminating its illicit nuclear program; and
(II) vital to the national security interests of the United States; and
(B) if the President determines he is able to make the certification described in subparagraph (A), make such certification to the appropriate congressional committees and leadership.