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Despite President Donald Trump announcing that the U.S. and Iran are set to have negotiation talks on Monday, Kalshi traders are not optimistic that the two nations will reach a nuclear deal anytime soon. 

The odds of a U.S. and Iran nuclear deal jumped for several Kalshi markets on Aug. 2, after Trump called off planned military strikes against Iran late Saturday night on Truth Social. The halt happened at the request of Saudi Arabia, United Arab Emirates, Qatar and Iran. 

After Trump called off the attacks, the likelihood on Kalshi that a nuclear deal will happen before January 2027 jumped to 29% early Sunday morning from 17% on Saturday evening. Similarly, as of early Sunday morning, Kalshi traders saw a more than 40% likelihood that a nuclear deal would be reached before March 2027. That's up from 20% Saturday evening.

The outcome for the market would be verified if the U.S. agrees, signs or accepts a nuclear deal with Iran, according to Kalshi's website.

Further, after Trump announced the U.S. and Iran would resume negotiation talks on Monday, Kalshi traders saw a lower likelihood of the two nations reaching an agreement over nuclear. All of Kalshi's market odds on when a nuclear deal will happen are under 50% – with the exception of the parties reaching an accord before January 2029, the furthest date out of any market. 

Earlier Monday, Iran's Foreign Ministry spokesman Esmail Baghaei said in a news conference that there is no immediate plan for talks with the U.S. 

Oil prices dropped after Trump's announcement on negotiation talks and the move to halt strikes against Iran. West Texas Intermediate futures for September delivery fell 6% to trade below $80 a barrel, while Brent crude futures for October delivery fell more than 4%.

Disclosure: CNBC and Kalshi have a commercial relationship that includes customer acquisition and a minority investment.