Feridun Sinirlioglu, a top Turkish diplomat, will travel to Bern and Washington "in the coming days to express our concern" over a ruling by Armenia's constitutional court, a Turkish Foreign Ministry spokesman was quoted as saying by Turkish English-language newspaper Hurriyet Daily News & Economic Review.
The ruling threatens a peace process that hit its high last October when Turkey and Armenia after decades of conflict signed two documents to re-establish ties and reopen the countries' mutual border.
Armenia's constitutional court upheld the legality of the documents but underlined that they can't contradict the official Armenian position that the 1915-1923 killings of up to 1.5 million Armenians under the Ottoman Empire constituted genocide, a label Ankara strongly rejects.
The spokesman vowed that Ankara was still eager to improve ties.
"There is no problem in Turkey's Armenian opening," he was quoted as saying. "But Armenia has a problem with its Turkey opening."
In Turkey, people are critical of Armenia's occupation of Nagorno-Karabakh, an enclave in neighboring Azerbaijan.
In 1993 Ankara severed ties with Armenia when it fought a war with Azerbaijan, a close Turkish ally. Observers expect some sort of political horse-trading between Turkey and Armenia on the genocide and Nagorno-Karabakh issues.