(Reuters) -U.S. Secretary of State Antony Blinken has spoken to the leaders of Armenia and Azerbaijan and reaffirmed Washington's support for a peace treaty between the South Caucasus neighbors, the State Department said on Sunday.
Yerevan suffered a major defeat last September when Baku's forces retook the region of Nagorno-Karabakh, which while part of Azerbaijan had a predominantly Armenian population.
Peace talks have become bogged down in issues including demarcation of the two countries' 1,000-km (620-mile) border, which remains closed and heavily militarized.
Blinken spoke to Azeri President Ilham Aliyev on Sunday and urged him "to keep up the momentum with his Armenian counterpart, reiterating U.S. willingness to support those efforts," the State Department said in a statement.
Aliyev's press service said on Sunday that foreign ministers of Azerbaijan and Armenia will soon hold a meeting in Almaty in Kazakhstan to continue negotiations.
"The president considers an important step that ... Azerbaijan and Armenia have begun the process of border demarcation," Russia's Interfax news agency cited the press service as saying.
In a separate call with Armenian Prime Minister Nikol Pashinyan, Blinken reaffirmed U.S. support for progress on a durable and dignified peace agreement, the department said, but did not specify when the call took place.
In his call with Aliyev, Blinken also welcomed the transfer to house arrest last week of a prominent Azerbaijani economist and opposition politician who has been imprisoned since last July while awaiting trial.
Azerbaijan has also detained a string of independent reporters since late last year. Several are now facing trial on charges unrelated to journalistic activity, such as smuggling.
"Secretary Blinken again urged Azerbaijan to adhere to its international human rights obligations and commitments and release those unjustly detained in Azerbaijan," the State Department said.