A senior U.N. official said she had urged Myanmar's military ruler to release political prisoners and stop executions on Wednesday, in a rare, high-profile visit that comes amid growing violence in the country.

Myanmar has been in turmoil since the military overthrew an elected government led by Nobel laureate Aung San Suu Kyi early last year and launched a bloody crackdown on peaceful protests and armed resistance movements that followed.

Noeleen Heyzer arrived in the capital Naypyitaw late on Tuesday and was greeted by foreign ministry officials, state media reported, before holding a meeting with junta chief Min Aung Hlaing on Wednesday.