An outspoken Republican senator is set to delay American approval of Finland's Nato application, which must be approved by all 30 Nato member countries.

Sen. Rand Paul from Kentucky has called for the United States to ignore Nato's Article 5, which automatically guarantees US aid to another member country that is under attack. He argues that any such action must require congressional approval.

Paul is pushing for the Senate to vote on an amendment to that effect - which has little support - before voting on the Nato applications of Finland and neighbouring Sweden.

That could delay the vote on the applications until after the legislature's summer recess, which is to begin on 8 August.

Mitch McConnell, a fellow Kentuckian who leads the Republicans in the Senate, told the US news site Politico that the Senate should finish the process before the month-long recess.

All 100 senators must support the bill for it to be fast-tracked. All Democrats have agreed to a quick vote on the Nato treaty. All Republican leaders also back prompt approval for the two countries to join the military alliance.

The delay called by Paul is a setback for Democratic Majority Leader Chuck Schumer as he seeks approval of a series of bills before the end of the summer break.

"Senators on both sides want to approve the Nato treaty for Finland and Sweden as soon as possible, as the West aims to push back against Russia's war in Ukraine," Politico reported on Wednesday.

On Wednesday, North Macedonia became the 19th Nato member state to ratify the accession protocols of Finland and Sweden.

The US House of Representatives approved the bids last week. All 18 'no' votes were from Republican lawmakers. However Senate approval is required for ratification.

Kyiv: Paul is a "Russian propagandist"

This week Ukraine added Paul's name to a list of American politicians, academics and activists Kyiv claims have promoted "Russian propaganda".

Last spring, Paul claimed that US President Joe Biden provoked Russia to invade Ukraine by backing Kyiv's right to apply for Nato membership.

Newsweek quoted Paul as saying that "you could also argue the countries they've attacked were part of Russia. Or part of the Soviet Union."

US Secretary of State Antony Blinken chastised Paul for the comments, stressing that there was no justification for Russia's attack on Ukraine five months ago.

19.07: Updated with 19th ratification.