Charles Maines

Putin said Khamenei would be remembered as a skillful leader who helped bring Russian-Iranian relations to new levels of cooperation.

Iran was key to helping Russia develop its domestic drone program after its full-scale invasion of Ukraine last

and last year the two sides signed a strategic cooperation agreement.

Yet Moscow's offered little beyond verbal criticism of U.S.-Israeli actions thus far, a tacit admission, analysts say, of the limits of Russian military resources more than four years into its war in Ukraine.

Charles Baines, NPR News, Moscow.

President Trump returned to office, vowing he could leverage his relations in Moscow and Kiev to resolve the conflict in short order.

Yet months of U.S.-led negotiations have bogged down over Russian demands for additional Ukrainian territory its forces do not hold and Ukraine's need for U.S.-backed security guarantees that Washington is yet to offer.

The Kremlin says its military will simply take what diplomacy doesn't deliver, despite Russian forces going up against overstretched Ukrainian defense's

Russian battlefield advances have come at a glacial pace and with heavy losses.

Charles Mains, NPR News, Moscow.

The trilateral talks marked the third such meeting in recent weeks.

Previous negotiations yielded several goodwill-generating prisoner swaps, but little clarity on how to put an end to the fighting.

Months of U.S.

efforts to negotiate an end to the conflict have bogged down over Russian maximalist demands on Ukrainian territory

including land not controlled by Russian forces, as well as Ukraine's desire for ironclad security guarantees from the U.S.

should it sign on to a peace deal.

Also unclear what U.S.

protections for Ukraine are on offer or what the Kremlin might accept.

On the eve of the talks, President Trump suggested the onus was on Kiev to make concessions, saying Ukraine better come to the table fast.

Charles Mainz, NPR News, Moscow.