US President Donald Trump has defended his "absolute right" to share information with Russia, following a row over classified material.
Mr Trump tweeted that he had shared "facts pertaining to terrorism and airline safety" and wanted Russia to do more against so-called Islamic State.
He met Russian Foreign Minister Sergei Lavrov in the Oval Office last week.
US media said Mr Trump had shared material that was passed on by a partner which had not given permission.
A report in the Washington Post said Mr Trump had confided top secret information relating to an IS plot thought to centre on the use of laptop computers on aircraft.
Mr Trump's move was not illegal, as the US President had the authority to declassify information.
The action drew strong criticism from Democrats and a call for an explanation from his own Republican party.
In his tweets early yesterday, Mr Trump said: "As President I wanted to share with Russia (at an openly scheduled W.H. meeting) which I have the absolute right to do, facts pertaining to terrorism and airline flight safety.
"Humanitarian reasons, plus I want Russia to greatly step up their fight against [IS] and terrorism."
It was not clear if Mr Trump was acknowledging having shared intelligence secrets with the Russian officials, thus contradicting White House statements, or whether he was simply trying to explain what had been discussed.
The BBC reports from Washington said this was a carefully constructed defence of the meeting, in which President Trump framed any revelation of intelligence information as a calculated move to advance US national security priorities.
After all, the controversy that swirled around the White House on Monday night was never legal, it was political, and this defence may be enough for Republicans to rally around, he added.
In a conversation with the Russian foreign minister and Russian ambassador Sergei Kislyak in the Oval Office, the president revealed details that could lead to the exposure of a source of information, officials told the Washington Post.
The intelligence disclosed came from a US ally and was considered too sensitive to share with other US allies, the paper reported.
Others at the meeting realised the mistake and scrambled to "contain the damage" by informing the Central Intelligence Agency (CIA) and the National Security Agency (NSA), says the Post.