The responses by Russia to U.S. proposals to end the crisis in Ukraine do not create the environment for a diplomatic resolution, the United States said Tuesday. U.S. Secretary of State John Kerry spoke to his Russian counterpart on Tuesday morning to discuss a series of questions that Washington delivered to Moscow over the weekend in an effort to find a diplomatic solution, the State Department said. Kerry "reiterated his willingness to continue to engage with Foreign Minister [Sergei] Lavrov, including this week, but that the environment has to be right and the goal must be to protect the immunity and sovereignty of Ukraine, and we didn't see that, obviously, in the responses that we received back," spokeswoman Jen Psaki told reporters. The top U.S. diplomat told Lavrov that "any further escalatory steps will make the window for diplomacy more difficult," Psaki said, adding that he also said "it is unacceptable that Russian forces and irregulars continue to take matters into their own hands."