Sen. Tom Cotton (R-AR) appeared on "Fox and Friends" this morning to discuss the open letter he and 46 of his Republican colleagues in the Senate are sending today to Iranian leaders about the ongoing nuclear negotiations between their country and the U.S.

"Many Iran experts say that Iran's leaders don't understand our Constitution," Cotton said. "So they need to understand that under our Constitution, Congress plays a very important role of approving international agreements. And any deal that isn't approved by the Congress won't be accepted by the Congress, now or in the future."

Cotton said he hopes more Republicans, Democrats and possible presidential candidates also sign the letter.

"We already have four Senators on the letter who are thinking about running for president," Cotton revealed. "Rick Perry said last week that he wouldn't honor a deal that doesn't go through Congress. I've spoken privately with other presidential candidates who might join us. And for that matter, I would encourage Hillary Clinton to join us in saying that Congress must approve any nuclear deal with Iran."

"Many Senate Democrats have been strong on this issue. They think that we need to approve any nuclear deal with Iran, but the White House is putting a lot of pressure on Senate Democrats to hold their fire," Cotton explained.

Cotton said they don't know yet what the final terms of the proposed agreement are, but he does know that National Security Advisor Susan Rice has already conceded that Iran will have a robust nuclear enrichment capability.

Cotton added that the president has said that this deal will have a sunset clause, perhaps as soon as ten years.

"Those two terms alone make this deal unacceptable, dangerous to the United States and dangerous to the world," Cotton stated.

Watch more above and read the open letter below.

An Open Letter to the Leaders of the Islamic Republic of Iran:

It has come to our attention while observing your nuclear negotiations with our government that you may not fully understand our constitutional system.  Thus, we are writing to bring to your attention two features of our Constitution—the power to make binding international agreements and the different character of federal offices—which you should seriously consider as negotiations progress.

First, under our Constitution, while the president negotiates international agreements, Congress plays the significant role of ratifying them.  In the case of a treaty, the Senate must ratify it by a two-thirds vote.  A so-called congressional-executive agreement requires a majority vote in both the House and the Senate (which, because of procedural rules, effectively means a three-fifths vote in the Senate).  Anything not approved by Congress is a mere executive agreement.

Second, the offices of our Constitution have different characteristics.  For example, the president may serve only two 4-year terms, whereas senators may serve an unlimited number of 6-year terms.  As applied today, for instance, President Obama will leave office in January 2017, while most of us will remain in office well beyond then—perhaps decades.

What these two constitutional provisions mean is that we will consider any agreement regarding your nuclear-weapons program that is not approved by the Congress as nothing more than an executive agreement between President Obama and Ayatollah Khamenei.  The next president could revoke such an executive agreement with the stroke of a pen and future Congresses could modify the terms of the agreement at any time.

We hope this letter enriches your knowledge of our constitutional system and promotes mutual understanding and clarity as nuclear negotiations progress.

Sincerely,

Senator Tom Cotton, R-AR
Senator Orrin Hatch, R-UT 
Senator Charles Grassley, R-IA      
Senator Mitch McConnell, R-KY     
Senator Richard Shelby, R-AL        
Senator John McCain, R-AZ
Senator James Inhofe, R-OK          
Senator Pat Roberts, R-KS  
Senator Jeff Sessions, R-AL 
Senator Michael Enzi, R-WY
Senator Michael Crapo, R-ID          
Senator Lindsey Graham, R-SC      
Senator John Cornyn, R-TX            
Senator Richard Burr, R-NC
Senator John Thune, R-SD 
Senator Johnny Isakson, R-GA
Senator David Vitter, R-LA 
Senator John A. Barrasso, R-WY    
Senator Roger Wicker, R-MS          
Senator Jim Risch, R-ID
Senator Mark Kirk, R-IL      
Senator Roy Blunt, R-MO    
Senator Jerry Moran, R-KS
Senator Rob Portman, R-OH          
Senator John Boozman, R-AR         
Senator Pat Toomey, R-PA 
Senator John Hoeven, R-ND
Senator Marco Rubio, R-FL 
Senator Ron Johnson, R-WI
Senator Rand Paul, R-KY
Senator Mike Lee, R-UT      
Senator Kelly Ayotte, R-NH
Senator Dean Heller, R-NV 
Senator Tim Scott, R-SC      
Senator Ted Cruz, R-TX      
Senator Deb Fischer, R-NE 
Senator Shelley Moore Capito, R-WV        
Senator Bill Cassidy, R-LA   
Senator Cory Gardner, R-CO          
Senator James Lankford, R-OK      
Senator Steve Daines, R-MT
Senator Mike Rounds, R-SD
Senator David Perdue, R-GA          
Senator Thom Tillis, R-NC  
Senator Joni Ernst, R-IA      
Senator Ben Sasse, R-NE    
Senator Dan Sullivan, R-AK