This action comes amid a strong increase in airstrikes from Russia. The call came just a day after Trump had a meeting that was seen as not very promising with Russian President Vladimir Putin.
According to a Telegram post, Mr Zelensky affirmed that the two sides have agreed to cooperate to enhance the ability to "protect the sky of Ukraine", especially through joint defense production, procurement and investment.
The discussion focused on reconnecting the supply chain of patriot air defense systems - a type of weapon that Ukraine considers the key to preventing Russian airstrikes.
A British newspaper said the call lasted about 40 minutes and was assessed as "very positive". President Trump is said to have pledged to check the status of US weapons planned to be delivered to Ukraine - a part of which has been suspended recently.
Mr Zelensky added that he and Mr Trump have agreed to arrange a meeting between groups of experts from both sides to continue strengthening air defense systems, while emphasizing that joint production cooperation is an urgent need for both countries.
The phone call comes as Russia launched its largest UAV attack since the start of the conflict on the capital Kiev, just hours after Trump spoke with the Russian president. The Ukrainian president called the attack "intentional, large-scale and propagandic".
The German government said Trump also had a phone call with German Chancellor Friedrich Merz on the same day, revolving around the situation in Ukraine, the possibility of increasing air defense aid and some trade issues between the two countries.
Under President Joe Biden, the US has provided patriot missile and ammunition complexes to Ukraine in the form of aid. However, President Trump - after taking office - criticized this approach and said that the US did not receive any corresponding benefits from Kiev, and at the same time profoundly adjusted relations with Ukraine.
