He was speaking to reporters during a break in marathon talks involving Russian President Vladimir Putin.

The four-way meeting, also being attended by the leaders of France and Germany, began late on Wednesday and continued into Thursday morning.

Thousands of people have been killed in the fighting in the east of Ukraine.

German Chancellor Angela Merkel and French President Francois Hollande are leading the peace initiative in Minsk.

After about 14 hours of overnight talks, Mr Poroshenko said there was "no good news yet".

He told reporters that Russia had set "conditions that I consider unacceptable". He declined to elaborate but added that there was "always hope" as talks were continuing.

They were set to focus on securing a ceasefire, withdrawal of heavy weapons and creating a demilitarised zone.

Russia has been accused of arming and reinforcing pro-Russian rebels in eastern Ukraine - a claim it denies.

While the Ukrainian government is seeking a demarcation line based on the failed ceasefire agreed on 5 September in Belarus, the rebels want a new truce to reflect the gains they have made in recent weeks, the BBC's James Reynolds reports from Donetsk.

Meanwhile the International Monetary Fund (IMF) has offered Ukraine a $17.5bn funding package (£10.5bn; 15.5bn euros) to help the country's struggling economy.

Alongside other sources, this would reach $40bn over a four-year period, IMC chief Christine Lagarde said.

Source: BBC