KYIV, Ukraine (AP) — Clinching a deal to end the Russia-Ukraine war “is far too complex to be done quickly,” a senior Kremlin official said Wednesday, as the U.S. labors to bring momentum to peace efforts and expresses frustration over the slow progress.

President Vladimir Putin is open to peace in Ukraine and intense work is going on with the United States, but the conflict is so complicated that the rapid progress which Washington wants is difficult to achieve,

Kremlin spokesperson Dmitry Peskov warned Wednesday that "a whole series of nuances" needs to be addressed before Russia will agree to any U.S.-brokered peace deal.