Mongolian President Tsakhia Elbegdorj has called on all parties to agree on forming a ruling coalition, after official results showed the opposition Democratic Party won most seats, but not enough for a majority.

There have been days of unease since the June 28 elections in which some parties said a new automated voting system to elect the Great Hural, Mongolia's 76-member parliament, had failed.

"The secretary is going to be very clear that we celebrate a succession of successful elections in Mongolia," a former Soviet satellite, a top State Department official told reporters travelling with Clinton.

Mongolia is sandwiched between Russia and China. After ending Soviet-backed rule in 1990, it has undergone a relatively peaceful and successful transition into a stable democracy.

Clinton arrived in Ulan Bator from Tokyo, where she used a global forum on Sunday to make a powerful plea for the rights of women in Afghanistan.