Trump is beating his head against a wall. Putin’s demands are essentially nonnegotiable, and if Trump doesn’t like it, he can lump it; Russia will just keep rollong over Ukraine. From Patrick Lawrence at unz.com:

President Donald Trump at a Salute to America celebration at the Iowa State Fairgrounds in Des Moines on July 3. (White House /Daniel Torok)
Presidents Donald Trump and Vladimir Putin have spoken by telephone numerous times since the former reassumed office seven months ago. Not much appears to have been accomplished by way of these exchanges, some of which have been lengthy, according to the accounts Washington and Moscow have provided afterward.
No progress toward a durable settlement to end the war in Ukraine. Talk and desultory diplomatic contacts with a view to repairing the profligate damage successive American administrations have done to U.S.–Russian relations, but no substantive advances. O.K., it is what it is, as we say. But there was something singularly conclusive about the telephone conversation the U.S. and Russian leaders had last Thursday.
I detect that a dead end has been reached.
Trump was trying once again to get Putin to agree to an “immediate and unconditional ceasefire” in Ukraine — “the quick end to the military action,” as Yuri Ushakov, the Kremlin’s senior foreign policy adviser, put it. Putin was trying once again to explain that the time has come to structure an enduring settlement by addressing — the Kremlin’s favored phrase these days — the “root causes” of the conflict.
Maybe it is the barrage of drones and missiles with which the Russians bombarded Kiev and other Ukrainian cities within a few hours of the Trump–Putin exchange that prompts me to think the two leaders or their diplomats are unlikely ever to get anywhere on the telephone or at the mahogany table.