As the United States and its allies provide Ukraine with increasingly sophisticated arms, Washington has held discussions with Kyiv about the danger of escalation if it strikes deep inside Russia, U.S. and diplomatic officials have said.
The behind-the-scenes discussions, which are highly sensitive and have not been previously reported, do not put explicit geographic restrictions on the use of weapons supplied to Ukrainian forces. But the conversations have sought to reach a shared understanding of the risk of escalation, three U.S. officials and diplomatic sources said.
"We have concerns about escalation and yet still do not want to put geographic limits or tie their hands too much with the stuff we're giving them," said one of the three U.S. officials, speaking on condition of anonymity.