US Secretary of State Hillary Clinton visited Azerbaijan on Wednesday for talks aimed at strengthening relations with the oil-rich state, amid a flare-up of violence on its border with Armenia.
Clinton arrived after gunbattles on the ex-Soviet states' mutual border this week killed eight soldiers -- five Azerbaijanis and three Armenians -- in one of the deadliest outbursts of violence in months.
The neighbours are locked in a bitter unresolved conflict over Nagorny Karabakh, an Armenian-controlled enclave inside Azerbaijan that was the focus of a bloody war in the 1990s.
Although this week's clashes erupted well to the north of the disputed region, Clinton was expected to reiterate a call for both sides to end the violence.
"The use of force will not resolve the Nagorny Karabakh conflict and therefore force must not be used," she said during a visit to Yerevan on Monday, pledging to deliver the same message to Azerbaijani leaders in Baku.
Local media in both Azerbaijan and Armenia however said there had been further exchanges of fire on Tuesday night, although no casualties were reported.
After arriving in Baku, Clinton immediately went into talks with Azerbaijani President Ilham Aliyev at his palatial residence overlooking the Caspian Sea.
The United States is a co-chair with Russia and France of the OSCE Minsk Group, which was set up after the 1994 Karabakh ceasefire to help bring about a peaceful resolution to the conflict.
But the conflict has remained unresolved for nearly two decades, leaving Armenia suffering economically due to closed borders with Azerbaijan and its ally Turkey, while Baku has grown richer on its Caspian Sea oil deposits.
The United States has sought to balance its relationship with both countries, pressed on one side by the large American Armenian community and Washington's strategic interests in the Caspian basin on the other.
Clinton planned to visit an oil and gas trade exposition being held in Baku, highlighting the $8 billion that US energy companies have invested in Azerbaijan since independence following the break-up of the Soviet Union.
Also expected to come up in her talks is Iran, which shares a border with Azerbaijan.
Although both countries are predominantly Shiite Muslim, there are political tensions between Azerbaijan's secular leadership and Iran's Islamic regime.