A meeting between President Barack Obama and Sens. Charles Schumer (D-N.Y.) and Lindsey Graham (R-S.C.) scheduled for Monday afternoon on immigration reform has been postponed and will be rescheduled later this week, thanks to flight cancellations in South Carolina.

“Senator Graham’s meeting with President Obama and Senator Schumer to discuss immigration reform has been postponed,” Graham’s communications director Kevin Bishop said in a statement. “Senator Graham was scheduled to fly to Washington this afternoon but his US Air flight from South Carolina was cancelled. The meeting will be rescheduled.”

Schumer and Graham have been working for months on a bipartisan outline for immigration reform. The two have searched for an additional Republican co-sponsor but have yet to bring one aboard. Immigration reform advocates are pushing for Schumer and Graham to introduce legislation before a March 21 rally on the issue on the National Mall, but Congressional aides say the road map has yet to be determined.