At a meeting at Lucca in Italy, the group said there must be an investigation into last week’s alleged chemical weapons attack in a rebel-held town before new measures could be adopted.
The Italian foreign minister, Angelino Alfano, said there was no consensus for fresh sanctions on Russia. Alfano said the idea had been raised by Johnson, but added that isolating Russia or pushing it into a corner “would be wrong”.
The G7 blames strongly supported US missile strikes that targeted a Syrian airbase last week in retaliation for an alleged chemical weapons attack.
Alfano said the US intervention had offered “a window of opportunity to construct a new positive condition for the political process in Syria”.
But he said a political rather than military process was “the only solution.”
His words masked a divide among G7 countries about how to deal with Syria and Moscow, the Guardian reported.
Johnson earlier said the G7 was considering new sanctions on Russian military figures to press Moscow to end military support for the Assad government. US officials in Washington have also raised that prospect.
But others want a more conciliatory approach. Germany’s foreign minister, Sigmar Gabriel, said Russia and Iran must be involved in any peace process to end Syria’s six-year civil war.
The Japanese foreign ministry spokesman, Masato Ohtaka, said: “In terms of dialogue and other political engagement I think a lot of countries think that Russia can play a key role.”
The G7 wanted to deliver a united message to Russia through the US secretary of state, Rex Tillerson, who heads to Moscow later on Tuesday.