ANKARA/YEREVAN, (Reuters) – Turkey and Armenia have  agreed on a road map to normalise ties after nearly a century of  hostility, a move quickly welcomed by the European Union and the  United States, but which could upset oil-rich Azerbaijan.

The deal, weeks after President Barack Obama urged Turkey to  resolve the issue, came on the eve of the commemoration of mass  killings of Armenians by Ottoman Turks in 1915. The two states  since last year have held high-level talks to restore ties.

“The two parties have achieved tangible progress and mutual  understanding in this process and they have agreed on a  comprehensive framework for the normalisation of their bilateral  relations,” the foreign ministries of Turkey and Armenia said.

The statement gave few clues on how Turkey and Armenia  planned to tackle the sensitive dispute over the 1915 killings.

Turkish and Armenian government sources said the two sides  had not signed any document, but had agreed in principle to move  ahead in establishing normal relations, which would include  reopening a border shut in 1993.

But a senior Western diplomat said the roadmap commits the  neighbours to establishing diplomatic relations, opening their  border gradually and establishing commissions to tackle  historical disputes over “weeks or months”.