Azerbaijan expressed concern on Thursday at the prospect of the border being opened between its old foe Armenia and Turkey, where U.S. President Barack Obama visits next week.
With growing signs of a thaw in relations between Muslim Turkey and Armenia after a century of hostility, the chances have improved sharply of Ankara opening the frontier it closed in 1993.
Turkey's closure of the 268 km (166 mile) border had been in solidarity with Azerbaijan, which was fighting Armenian-backed separatists over the breakaway Nagorno-Karabakh region — a festering conflict that remains unresolved.
"If the border is opened before the withdrawal of Armenian troops from the occupied territories of Azerbaijan, it would run counter to Azerbaijan's national interests," Azeri Foreign Minister Elmar Mamedyarov told Azeri ANS television
"We have conveyed this opinion to the Turkish leadership," he said, adding that Turkey accepted Azerbaijan's concerns.
Turkey — Baku's principal ally in the frozen conflict — has no diplomatic ties with Armenia and a relationship haunted by the killings of hundreds of thousands of Armenians in Ottoman Turkey during World War One.
But both say they are close to a breakthrough on "normalising relations", which could lead to the opening of the border. Such a step would have major significance for Turkey's role as a regional power, its European Union membership bid and for energy flows from the Caspian Sea to Europe.
Analysts and local media reports suggest an announcement could come this month.
OBAMA VISIT TO TURKEY
They say the timing is linked to the visit next week to Turkey by Obama, who pledged during his election campaign to call the World War One killings genocide. Turkey denies there was a genocide, saying the deaths were the result of inter-ethnic conflict that also killed Muslim Turks.
Obama's April 5-7 visit is an acknowledgement of Turkey's regional reach, economic power and status as a secular Muslim democracy.
NATO ally Turkey could help Washington in confrontations and conflicts that stretch from Israel to Afghanistan.
Diplomats say Azerbaijan fears a Turkish-Armenian rapprochement would weaken its hand in the Nagorno-Karabakh dispute.
But landlocked Armenia, reeling from the effects of the global crisis and its ally Russia's drift into recession, would derive enormous economic benefits from the opening of the border and the potential restoration of rail links.
Western-backed pipelines pumping oil and gas from the Caspian Sea to Turkey's Mediterranean coast bypass Armenia and instead bend north through neighbouring Georgia.
Georgia's security as an energy transit route was severely tested during last year's five-day war with Russia, and Armenia stands to present itself as an attractive alternative.
