A new administration can rescind the current Petroleum Agreement

If an agreement is signed between the Government and a third party, can a new administration rescind that agreement?
After reviewing what the Trump administration did with the Paris Club agreement and the Iran Nuclear Deal agreement, I am of the opinion that a new administration in Guyana can do the same.
President Obama’s administration signed the agreements mentioned above, and they took legal effect. The problem, however, is that President Obama did not seek the approval of Congress to ratify those agreements. Had Congress ratified those agreements, President Trump could not end the agreements as he did unless Congress gives him the authority.
The NAFTA agreement cannot be rescinded unless Congress votes on it. President Trump’s team has completed a new USMCA (United States Mexico Canada Agreement), but that new agreement cannot take effect unless Congress ratifies it, thus making NAFTA redundant.
I have done some reflection on the Petroleum Sharing Agreement between the Government and the oil companies. The Government signed this agreement, but it was not presented to the National Assembly for ratification. Following the precedents mentioned above in the United States, I am of the firm opinion that a new administration can rescind the current Petroleum Agreement.
I am hoping that the new administration will follow suit on my recommendation. I am also sure the Courts will get involved. We should give notice to the parties to this lop-sided agreement that we will pursue this path.

Sincerely,
Charles Sugrim, CPA