A Russian wanted in Britain over the death of ex-spy Alexander Litvinenko will not appear before an inquiry into his poisoning, the probe heard Tuesday, dealing it a setback days before its conclusion.

After several days of uncertainty, Dmitry Kovtun failed to give evidence via video link from Moscow to the inquiry at London's High Court by a 1000 GMT deadline set by its chairman.

Ukraine's truce monitors reported Tuesday coming under "targeted" fire in the past few days in incidents that have forced them to review future operations in the war-torn state.

The Organization for the Security and Cooperation in Europe (OSCE) remains at the heart of global efforts to end the 15-month conflict between Western-backed Kiev and pro-Russian insurgents that has already claimed more than 6,500 lives.

At least two people were killed Monday and a regional power station was knocked out of action after being damaged by shelling in Ukraine's pro-Russian separatist east.

Ukrainian military spokesman Andriy Lysenko said one soldier had died and seven were wounded across the eastern industrial war zone in the past 24 hours of clashes.

A Russian businessman wanted in Britain over the death of ex-spy Alexander Litvinenko was on Monday given a final chance to give evidence to the inquiry into his death.

Dmitry Kovtun had been due to appear via video link from Moscow for three days from Monday, after reversing a previous decision not to do so in March, but has given a series of reasons for being unable to testify.

The United States is to begin training Ukrainian army troops in an expansion to its military involvement in the divided country, the State Department said Friday.

U.S. troops have already deployed in small numbers to Ukraine to train National Guard forces, but under the new plan would also take on regular military units.

Ukraine on Friday reported a soldier had died in clashes with pro-Russian rebels in the east of the country, despite another international bid to find a solution to the 15-month conflict.

Ukrainian army spokesman Andriy Lysenko said three servicemen were also wounded across the separatist east of the former Soviet state.

Ukraine on Friday made a crucial Eurobond interest payment that kept the war-torn country from slipping into technical default and potential isolation from global credit markets.

Two sources close to the situation told Agence France Presse that money to cover the $120 million (110 million euro) payment was transferred as soon as business hours opened in Kiev. The $2.6 billion note matures in July 2017.

Ukraine vowed to fight on Wednesday to ensure the return and trial of its exiled Russian-backed president after his name was unexpectedly removed from Interpol's international most wanted list.

The former Soviet state's leader Viktor Yanukovych was toppled by a wave of bloody protests and fled to Russia with the help of Kremlin security agents in February 2014.

Russia on Tuesday announced that the trial of Ukrainian pilot Nadiya Savchenko, whose politically charged case  has become emblematic of bitter tensions between Kiev and Moscow, will begin later this month. 

The trial of the 34-year-old helicopter navigator and Ukrainian lawmaker, who faces up to 25 years in prison for her alleged involvement in the killing of two Russian journalists, will begin on July 30 in the southern Russian city of Donetsk, a local court said. 

Russia said Monday it has introduced an alternative U.N.resolution opposed to creating a tribunal that would prosecute those responsible for the downing of Malaysia Airlines flight MH17 over rebel-held east Ukraine.

The Netherlands, whose citizens made up the majority of the 298 people killed in the July 2014 disaster, is working with Malaysia and other countries to create an international tribunal.