So far Trump's promises, threats and cajoling have failed to shift the Kremlin's position, and the stubborn diplomatic stalemate remains in place. Meanwhile, Ukraine is losing more territory on the front line, although there is no sign of a looming collapse of its defenses.

U.S. President Donald Trump’s special envoy Steve Witkoff was expected in Moscow in the middle of this week, just before Trump’s Friday deadline for the Kremlin to stop the killing or face potentially severe economic penalties from Washington.

President Trump is rattling the U.S.’s formidable nuclear saber amid his growing frustration with Russian President Vladimir Putin’s refusal to halt the war in Ukraine, just days ahead of Trump’s deadline for a ceasefire.