British Prime Minister Boris Johnson on Wednesday said he had agreed new deals with Sweden and Finland to bolster European security, pledging to support both countries' armed forces should they come under attack.

"We are steadfast and unequivocal in our support to both Sweden and Finland and the signing of these security declarations is a symbol of the everlasting assurance between our nations," Johnson said in a statement released to coincide with his visits to both countries.

The government statement added: "The Prime Minister will set out the UK's intention to support the two nations' armed forces should either face crisis or come under attack."

(Reporting by William James, Editing by Kylie MacLellan)