US Secretary of State Mike Pompeo is scheduled to meet the foreign ministers of Azerbaijan and Armenia in Washington on Friday in a new attempt to end nearly a month of bloodshed in which Russian President Vladimir Putin said more than 4,000 people may have been killed. The collapse of two Russia-brokered ceasefires has dimmed hopes of a quick end to fighting that broke out on September 27 over Nagorno-Karabakh, a breakaway territory which is within Azerbaijan but is controlled by ethnic Armenians. World powers want to prevent the fighting sparking a wider war that draws in Turkey and Russia, and are concerned about the security of pipelines in Azerbaijan that carry Azeri gas and oil through the South Caucasus to world markets. Azerbaijan's defence ministry reported fighting in several areas on Friday, including territories close to the line of contact that divides the sides. Armenia's defence ministry also reported fighting in several areas and said the town of Martuni in Nagorno-Karabakh was shelled again during the night. Mr Pompeo is scheduled talks with Azeri Foreign Minister Jeyhun Bayramov at the State Department at 9.30am before meeting the Armenian Foreign Minister Zohrab Mnatsakanyan an hour later. It is not clear whether the two former Soviet republics' ministers will meet directly. "I very much hope that our American partners will act in unison with us and will help the settlement," Russian President Vladimir Putin said on Thursday. He said he spoke to leaders of Armenia and Azerbaijan several times a day by phone. Mr Putin said Moscow believed more than 2,000 people had been killed on each side during the recent flare-up. The confirmed toll on both sides is just under 1,000 including civilians, although the number would be higher because Azerbaijan does not report military casualties. Mr Pompeo said this week he hoped a diplomatic solution and the "right path forward" could be found as the United States, France and Russia press on with mediation efforts they have led for decades. Armenian Prime Minister Nikol Pashinyan has said he can see no diplomatic resolution of the long-running conflict at this stage. Azeri President Ilham Aliyev says the prospects of reaching a peace settlement are "very remote", and demanded promises that Azerbaijan will be handed back control of Nagorno-Karabakh. Armenians regard Nagorno-Karabakh as part of their historic homeland and accuse Azerbaijan of making a land grab in the recent fighting. The decades-old conflict led to a 1991-94 war in which about 30,000 people were killed and Azerbaijan’s troops were pushed out. Azeri forces have been bolstered by weapons bought from Turkey, as well as Syrian fighters from Turkish-allied rebel groups. Turkey has said it would send soldiers and provide military support for Azerbaijan if such a request were made by its ally. Mr Pompeo last week accused Turkey of inflaming the situation with its military support for Azerbaijan. Mr Putin said Russia, which has a defence pact with Armenia, disagreed with Turkey on Nagorno-Karabakh, but both countries needed to find a compromise.