Sen. Joe Donnelly, D-Ind., visited the Eastern European nations Ukraine and Georgia this week, according to his office.
Donnelly, a member of the Senate Armed Services Committee, met Monday in Kiev with Ukrainian Defense Minister Stepan Poltorak, Ukrainian security forces and U.S. Ambassador to Ukraine Marie Yovanovitch.
His office said Donnelly’s goal was "to reiterate American support for Ukrainian sovereignty in the face of an increasingly hostile Russia."
Donnelly also sought "to highlight the enduring importance of the Nunn-Lugar Cooperative Threat Reduction Program," his office said.
The program, established by legislation authored by then Sens. Richard Lugar of Indiana and Sam Nunn of Georgia and enacted by President George H.W. Bush on Dec. 12, 1991, has dismantled thousands of nuclear, chemical and biological weapons in the former Soviet Union. Donnelly replaced Lugar in the Senate in 2013.
Donnelly later went to the nation of Georgia, where he met with government leaders and security forces, toured facilities tasked with stopping the trafficking of nuclear and radiological material and visited the Richard G. Lugar Center for Public Health Research.
"Twenty five years ago, Senator Lugar led a bipartisan effort to make the world safer by keeping weapons of mass destruction out of the hands of dangerous actors. I am proud to help ensure that work continues today," Donnelly said in a statement.