Senate Majority Leader John Thune warned President Vladimir Putin on Thursday that if he does not "make a serious proposal for an immediate ceasefire" with Ukraine, the Senate will pass new sanctions against the Russian government. -snip- "If Russia is not willing to engage in serious diplomacy, the Senate will work with the Trump administration to consider additional sanctions to force Putin to start negotiating," Thune said Thursday. This comes the same week Secretary of State Marco Rubio warned senators in a hearing that if "you start threatening sanctions, the Russians will stop talking." -snip- The bill also would set...