Sen. John McCain (R-Ariz.) and a group of senators are slated to travel to Ukraine on Thursday to show support for the new interim government there. 

The meeting comes ahead of a planned referendum in Crimea on Sunday to secede from Ukraine and join Russia — something the U.S. has said would violate the country’s constitution. 

McCain’s office said the group would be meeting with members of the interim government and other stakeholders Thursday through Sunday. 

{mosads}The delegation will be made up of a group of eight senators from both parties. Aside from McCain, those traveling to Ukraine are Sens. Dick Durbin (D-Ill.), John Barrasso (R-Wyo.), John Hoeven (R-N.D.), Ron Johnson (R-Wis.), Chris Murphy (D-Conn.), Jeff Flake (R-Ariz.) and Sheldon Whitehouse (D-R.I.).

McCain and Murphy also visited the country in December as protests flared in Ukraine. In February, President Viktor Yanukovych fled the country and Russian troops invaded the Crimea peninsula. 

McCain’s office said it did not have specifics on the agenda when asked which parts of the country the delegation would be visiting. 

Ukraine Prime Minister Arseniy Yatsenyuk will meet with President Obama and members of Congress on Wednesday.

Meanwhile, Secretary of State John Kerry is set to meet in London with Russian Foreign Minister Sergei Lavrov on Friday.