"The challenge is to get final approval of our pre-clearance so we can start moving cargo and passengers by rail, " Shumlin said, but it's up to the federal governments in both countries to smooth the border crossings.
Network Rail said the spoil heap had stopped moving and it had been able to survey the damage, which it said was "a lot worse than we originally thought".
Mr. Srivastava said apart from production issues, there are also significant difficulties in moving coal from mines to power stations due to a shortage of rail wagons for hauling the dry fuel.