He said Trump would go ahead with the meeting "regardless of political criticism", the medium added.
"I think we'll be talking about Syria, Ukraine, and many other subjects".
The two leaders have met twice previous year on the sidelines of global summits.
The announcement came just after Trump on Thursday morning launched yet another broadside on social media that appeared more concerned about perceived rogue elements inside the Federal Bureau of Investigation than attempted Russian interference in the last election.
"Because that would fulfill Trump's anti-Iran position with the JCPOA [the Joint Comprehensive Plan of Action - the nuclear deal from which Trump pulled out], it would fulfill Israel's security interests, which, in the absence of a clear and identifiable Syria strategy, what we have right now is Israel's policy in Syria", said Weber.
The summit is being seen by some as an attempt by Putin to try to lift some of the sanctions imposed on Russian Federation after it annexed Crimea in 2014, its support of Ukrainian separatists and alleged meddling in the 2016 USA presidential elections.
President Donald Trump pushed Russia's version of events on alleged election meddling on Thursday, with a tweet that advanced conspiracy theories while questioning United States law enforcement and intelligence agencies.
After those talks, Mr Trump said he believed Mr Putin's denials Russian Federation had meddled in the 2016 U.S. presidential election - remarks Mr Trump later backed away from.
The Ukrainian presidential administration did not reply to a request for comment, but political analysts there said Russian Federation was unlikely to consider a deal on Ukraine until after Ukrainian presidential and parliamentary elections next year.
The tweets came just ahead of the Kremlin announcement that Trump would meet one-on-one with Putin July 16 in Helsinki, after taking part in the annual North Atlantic Treaty Organisation conference and visiting Britain.
Bolton told reporters he expected Moscow's meddling in USA politics to be discussed at the summit.
When is the July 16 U.S. -Russia summit?
At the time, one United States defense official directly familiar with the ISIS campaign said it was unclear what the President meant by the comments, adding that the military's current assessment is that now is not the time to consider withdrawing, citing numerous challenges in Syria.
Both leaders wanted to use the summit to improve relations between their countries, Mr Bolton said.
Finland served as the venue for 1975 meetings between U.S. President Gerald Ford and Soviet leader Leonid Brezhnev.
It is unclear what the White House hopes to get out of the meeting beyond a better relationship with Moscow.
"Keep in mind, the Russians said if you bomb Assad this is the beginning of World War III".
The official also noted that the USA still needed to decide on a policy with regard to Assad's future and Russia's continued military presence in the county as additional complicating factors. He assured reporters that USA positions on Russia's sovereignty over Crimea (not recognized) and sanctions on Moscow (still in effect) had not changed. "Had eight years of that, kind of exhausted of it", said Graham, who serves on the US Senate's Armed Services committee. U.S. President Donald Trump's national security adviser is due in Moscow Wednesday to lay the groundwork for a possible U.S. -Russia summit.