A last-gasp deal to salvage the North American Free Trade Agreement (NAFTA) does nothing to improve the prospect of a meaningful breakthrough in the U.S.-China trade war, one market expert told CNBC on Monday.

Just hours before a midnight deadline, U.S. and Canadian officials reached a deal to revamp NAFTA, which also includes Mexico, after more than a year of grueling negotiations.

Until recently, Canada appeared to be on the brink of being excluded from a final agreement but negotiations over the weekend eventually culminated in all three countries signing up to the new United States-Mexico-Canada (USMCA) accord.

However, one market expert cautioned the new NAFTA deal shouldn't be seen as a sign that there could soon be a breakthrough in troubled trade relations between the U.S. and China.

"I do believe that unfortunately the China story is a lot more complicated (than NAFTA talks)," Luis Costa, head of CEEMEA FX and rates strategy at Citibank, told CNBC's "Squawk Box Europe" on Monday.