President Donald Trump’s suggestion that he may let Russia and Ukraine keep fighting has left US lawmakers in an awkward spot over their plan to force a ceasefire with “bone-crushing” sanctions against Moscow.

The White House reportedly asked Sen. Graham to insert waivers into the bill allowing Trump to choose which entities get sanctioned and changing the word "shall" to "may."

The bill, backed by more than 80 senators, would impose more sanctions on entire sectors of Russian economy and spike U.S. tariffs on countries buying Russian oil. However, Trump is said to worry that the measure could harm pursuit of détente with Moscow.