Toyota is expected to announce a 16 percent drop in its quarterly operating profit, according to analysts surveyed by Thomson Reuters I/B/E/S, while Nissan last week posted an nearly 13 percent slide in profit, dragged by rising incentives to sell its cars in the United States.
The two have also agreed to join forces to develop electric auto technology.
Earlier in the year, Trump - who had campaigned for the White House on promises to increase manufacturing and expand employment for American workers - criticised Toyota's plan to manufacture its Corolla model at a new $1bn plant now under construction in Mexico.
Toyota has invested $961 million in the Blue Springs plant, which employs 2,000 workers.
"New players from totally new business are challenging us", he said at a press conference.
Toyoda said it will go on the "offensive" by investing more in autonomous driving and artificial intelligence and is considering mergers and acquisitions as a route to expansion. Corolla production also is done at a plant in Canada.
"Toyota and Mazda have been working more closely together, so it is no surprise they will have a plant together", Autotrader.com analyst Michelle Krebs said, adding that Mazda had been searching for USA manufacturing capacity.
The announcement is likely to be viewed as a victory for President Trump who has been pushing foreign automakers to make more vehicles in the U.S.
The final location has not yet been picked but both auto manufacturers hope the plant will build 300,000 vehicles annually and employ 4,000 workers.
"We're in the process of preparing for our current volumes to be projected, and at this moment, we don't see any big change for us".
Subaru produces just over 1 million vehicles annually at its plants in Japan and the United States, compared with Toyota's roughly 10 million at plants across all major continents.
Toyota and Mazda said Friday that they would combine forces on key next-generation technology.
Toyota and Mazda continued: "Pending approvals and authorisation by relevant government agencies, the companies will begin to examine detailed plans with the goal to starting operations of the new plant in 2021". The joint venture would cost approximately $1.6bn, equally funded by Mazda and Toyota, and create up to 4,000 jobs.
Toyota said it is assuming an average USA dollar rate of 110 yen and euro rate of 124 yen for the year, compared to earlier estimates of 105 yen and 115 yen, respectively. As a result, Toyota's new factory in Mexico will instead shift to production of the Tacoma pickup truck instead.