Those talks have produced what Kiev says is a mutual understanding on key aspects of the peace plan, intended to end an insurrection by separatist rebels who want to join parts of Russian-speaking east Ukraine with Russia.
Scores of people have been killed in the crisis, which flared after Poroshenko's predecessor was overthrown in February and fled to Russia, which later annexed the Crimea region from Ukraine.
Disagreement on price mechanism
The latest gas talks ended early on Tuesday without a deal on the future price Moscow would charge Kiev.
Ukraine wants to change the 2009 contract that locked Kiev into buying a set volume of gas, whether it needs it or not, at $485 per 1,000 cubic metres - the highest price paid by any client in Europe.
Moscow dropped the price to $268.50 after Ukraine's then-President Viktor Yanukovich turned his back on a trade and association agreement with the European Union last year, but reinstated the original price after he was ousted in February.
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Ukrainian Energy Minister Yuri Prodan said the negotiations had stumbled over a Russian price mechanism proposal, which would link lower prices to an export duty.
Russia has floated the idea of scrapping its export duty for gas exports to Ukraine at the amount of $100 per 1,000 cubic metres, introduced after Moscow annexed Crimea, to reduce the price for the neighbouring country.
Russian Energy Minister Alexander Novak said on Tuesday he had proposed "a very constructive plan, which we believe all stakeholders could and should accept".
Moscow has said Ukraine must pay off some of its debt before it can talk about price. Kiev paid off $786 million of its debts in late May and Russian officials have suggested it could pay off a $1.45 billion for November and December debts and a further $500 million as a part of a bill for April and May deliveries.
"The Russia-Ukraine gas tensions are not over yet, and will likely continue for a while, further threatening the stability and reliability of Russian gas transit to the EU via Ukraine," analysts from Moscow-based Alfa bank said in a note.