Language mismatch between SAP XI & the ECC

Hello experts,

I have a situation where XI converts text messages of encoding type UTF-8 with some russian characters for description to IDOCs & post them in ECC system.The transaction is successful. when the payload on the output end is examined in SXMB_MONI, the characters are russian but examining the same in WE21 of the receiver ECC system, the russian characters are replaced with  '#'s & '?'s.

Please guide to solve the issue.

Thanks in advance

Sam