Russia's ambassador to the United States says that Presidents Donald Trump and Vladimir Putin discussed "concrete proposals" for resolving the conflict in eastern Ukraine during their summit in Helsinki.
Anatoly Antonov spoke on July 20, a day after Bloomberg quoted sources as saying that Putin told Russian diplomats he had proposed to Trump that a referendum be held in the region, where Russia-backed separatists hold parts of two provinces.
"This issue was discussed," Antonov said, apparently referring to the conflict itself and not a proposal for a referendum.
He said that "concrete proposals were made on how to resolve this issue," but did not describe them.
Trump has said on Twitter that he and Putin discussed the situation in Ukraine at the July 16 summit in Helsinki, but has not mentioned a potential referendum or provided any other details related to Ukraine.
More than 10,300 people have been killed since April 2014 in the conflict between Ukrainian forces and the Russia-backed separatists in Ukraine's eastern regions of Donetsk and Luhansk.
Moscow's takeover of Ukraine's Crimean Peninsula and its support for separatists in eastern Ukraine prompted the United States, the European Union, and others to impose sanctions on Russia.
Russia seized Crimea in March 2014 after sending in troops, taking over key facilities, and staging a referendum deemed illegitimate by at least 100 countries in the United Nations.
The Bloomberg report cited two people who attended a closed-door speech by Putin to Russian diplomats on July 19.
The report said Putin told the diplomats that he had agreed not to disclose the referendum plan publicly, in order to give Trump time to consider it.
There is no provision for a referendum in Minsk II, a European-brokered cease-fire and peace deal signed by Russia, Ukraine, and the separatist leaders in Donetsk and Luhansk in February 2015.
Russia, Ukraine, and Western countries all support the Minsk agreement publicly, but implementation has been slow and Ukraine and Russia accuse each other of thwarting efforts to carry it out.
Russian Foreign Ministry spokeswoman Maria Zakharova declined to comment on Putin's reported proposal for a referendum, saying on July 20 that it was beyond her competence to comment on details of the talks between Trump and Putin.
But she added that "if the global community, first and foremost the United States, has failed to make Kyiv implement the Minsk Agreements, then other options to resolve [the conflict] may be discussed."
At a joint press conference with Trump following their talks in Helsinki, Putin repeated Russian calls for the United States to press Kyiv harder to implement the Minsk agreement.
U.S. officials have repeatedly said that Russia must do much more to implement the agreement and create conditions under which it could succeed.
Antonov called the Helsinki summit "a key event" and said that Putin and Trump should continue to be in contact after their summit.
He said he was not aware of an invitation from Trump for Putin to visit Washington later this year, but stressed that Moscow was ready to discuss such a visit.
In a tweet on July 19, White House spokeswoman Sarah Sanders wrote that Trump "asked [national security adviser John Bolton] to invite President Putin to Washington in the fall and those discussions are already under way."