U.S. President Barack Obama could join the Normandy quartet for settling the situation in eastern Ukraine, if invited, U.S. Ambassador to Russia John Tefft said on Ekho Moskvy radio on Tuesday.

If Obama were invited he would gladly agree to participate in this process, Tefft said.

The Normandy quartet is currently comprised of Russia, Ukraine, France and Germany.

Tefft said he had no direct information from Obama on the U.S. president's attitude to possible work in the Normandy Format, but added that Obama's opinion could be positive.