ISTANBUL — Ukrainian President Volodymyr Zelenskyy warned that a prolonged U.S.-Israeli war on Iran could erode American support for Ukraine as Washington's global priorities shift. Zelenskyy made the remarks in Istanbul, where he held talks with Turkish President Recep Tayyip Erdogan a day after Erdogan spoke with Russian President Vladimir Putin.

"We have to recognize that we are not the priority for today. That's why I am afraid a long (Iran) war will give us less support," he said. He added that Ukraine expects reduced deliveries of U.S.-made Patriot air defense missile systems. "The package — which is not very big for us — I think will be smaller and smaller day by day," he said.

The conflict in Iran has drawn in much of the wider Middle East and diverted military stockpiles, leaving Ukrainian cities more exposed to ballistic strikes. Surging oil prices driven by Iran's closure of the Strait of Hormuz are boosting the Kremlin's oil revenues and strengthening Moscow's capacity to sustain its war effort. Russia is one of the world's main oil exporters, and Asian nations are increasingly competing for Russian crude oil.

Zelenskyy had been counting on European partners to help make Patriot purchases despite tight supply and limited U.S. production capacity. Ukraine needs the air defense systems as Russian forces have bombarded urban areas since their full-scale invasion more than four years ago, killing thousands of civilians. Russian forces have also targeted Ukraine's energy supply to disrupt industrial production of drones and missiles and to deny civilians heat and running water in winter.

On the diplomatic front, U.S.-brokered talks between envoys from Moscow and Kyiv ended in February with no breakthrough. He said Russia was trying to prolong negotiations while continuing its invasion. He said Ukraine is in contact with U.S. negotiators about a potential deal to end the war and has continued to press for stronger security guarantees. He has insisted that Ukraine will not agree to a territorial compromise or give up land.

During the Istanbul meeting, he said he and Erdogan discussed peace talks and a possible meeting of leaders in the city. He also said new defense deals between Ukraine and Turkey could be signed soon.

Russia occupies about 20 percent of Ukraine, including the Crimean Peninsula, which it seized in 2014. Along the roughly 1,250-kilometer front line stretching across eastern and southern Ukraine, Ukrainian defenders are preparing for a new offensive by Russia's larger army. Oleksandr Syrskyi, commander-in-chief of Ukraine's armed forces, said "Russian troops have in recent days made simultaneous attempts to break through defense lines in several strategic areas."