President Volodymyr Zelenskiy says he aims to have a plan ready in November to enable Ukraine to hold a second international summit on his vision of peace in the country and says representatives of Russia should attend.
Ukraine hosted delegations from 92 countries at a first summit in Switzerland last month to advance its blueprint for peace.
Russia, which invaded Ukraine in February 2022, was not invited to the event and dismissed it as a non-starter.
"I set a goal that in November we would have a fully ready plan," Zelenskiy told a press conference in Kyiv.
"I think that representatives of Russia should be at the second summit."
He made the remarks after returning from a visit to Washington DC for a NATO summit last week.
US officials discussed potential diplomatic negotiations with Zelenskiy during the summit, State Department spokesman Matthew Miller said but added decisions on peace talks were Ukraine's to make.
"We've always supported diplomacy when Ukraine is ready but it has never been clear that the Kremlin is ready for actual diplomacy," Miller said at a press briefing.
Ukrainian officials have said previously that Russian representatives could be invited to a follow-up summit.
A Russian deputy foreign minister said last week that its representatives would not attend a follow-up summit but the Kremlin has been less categorical and said there was "no precise substance" regarding the idea of a second summit.
The first summit discussed three of 10 points advanced by Ukraine as Zelenskiy's peace "formula," including food security, nuclear safety and the release of prisoners of war and children.
Ukrainian officials have said a second summit would discuss a plan devised in advance by dozens of countries divided into working groups.
Zelenskiy said officials were likely to meet in Qatar at the end of July or start of August to shape a stance on energy security.
A meeting on food security was likely in Turkey in August and another in Canada in September on POWs and children, he said.
On the battlefield, Russian forces have been edging forward in the east, exploiting an advantage in troop numbers and equipment.
Ukraine says its own defences have been bolstered by foreign arms deliveries in recent months.
It is also widely expected to soon receive a first batch of F-16 fighter jets from its allies.
Zelenskiy said Ukraine would receive some of the fighter jets this northern hemisphere summer and more before the end of the year.
He said he could not disclose how many there would be exactly.
"There will not be enough. They will certainly strengthen us but will there be enough of them to fight at a level with the Russian air force? I think they will not be enough. We are anticipating a larger quantity," he told reporters.
Ukraine has said it needs at least 128 F-16s.
The country has also stepped up its mobilisation effort to enlist more civilians into the armed forces.
Zelenskiy said the military had informed him that "everything is going according to plan" but that there was a need for an expansion of training.
"Regarding training facilities, there are not enough," he said.
"They are currently being enlarged."
with DPA