Trump: 'I have the absolute right' to share information with Russia

Democrats says action 'jeopardises US national security'

Trump administration officials state claims are 'false'

Republican Bob Corker: Trump White House 'in downward spiral'

Donald Trump has defended sharing classified information with Russian officials, saying he had the "absolute right" to do so for "humanitarian reasons" and because he wants Russia to step up its fight against Isil.

The US president revealed highly classified information to the Russian foreign minister and ambassador during a meeting at the White House last week, it was reported on Monday night.

The US president's actions jeopardised a critical source of intelligence on the Islamic State of Iraq and the Levant terror group, the Washington Post reported, citing unnamed US officials.

If confirmed, it would also call into question the ability of the US to protect its intelligence sources.

The Trump administration immediately rejected the claims as "false", while several Republicans and Democrats expressed alarm that a US president could share high-level intelligence with Russia.