Russia is withdrawing from the United Nation's tourism body, the UN World Tourism Organization said Wednesday ahead of a vote to suspend Moscow's membership over its invasion of Ukraine.

"Russia has announced its intention to withdraw from UNWTO," the UNWTO  said in a tweet, adding that Russia's suspension "is effective immediately".

The UNWTO announced in March that it wanted to suspend Russia over its invasion of Ukraine.

The decision must be approved by two-thirds of its 159 member states at a two-day extraordinary general assembly which got underway in Madrid on Wednesday.

The UNWTO said the vote will go ahead even though Russia has said it is withdrawing from the body to give member states "their say".

The body said it is the first time it has met to consider the suspension of one of its members.

"Our statues are clear: promotion of tourism for peace and universal respect for human rights," secretary general Zurab Pololikashvili tweeted.

"Only members that abide by this can be part of UNWTO," said the former Georgian economic development minister whose country was invaded by Russia in 2008.

An intergovernmental body that promotes tourism and facilitates international trade between nations, the UNWTO has been based in Madrid since it was founded in 1975.

The agency, which employs nearly 150 people, has warned that the conflict in Ukraine will delay the global tourism sector's uneven recovery from the impact from the Covid-19 pandemic.

It estimates the disruption of Russian and Ukrainian outbound travel alone could cause losses of up to $14 billion in tourism revenues this year, with the impact felt most strongly in island and coastal destinations.

Russia's invasion of Ukraine, launched on February 24, has left thousands dead or injured, reduced towns and cities to rubble, and forced more than five million people to flee abroad.

Moscow calls its actions a "special operation" to disarm Ukraine and protect it from fascists.

Ukraine and the West say this is a false pretext for an unprovoked war to seize territory in a move that has sparked fears of wider conflict in Europe unseen since World War II.