Prime Minister Boris Johnson has joined other world leaders for a virtual United Nations event pledging to reverse the loss of wildlife by 2030.

The Government has announced plans to protect 30% of the UK’s land by the end of the next decade, with an additional 400,000 hectares of land in England protected to support the recovery of nature.

Mr Johnson has signed up to the Leaders’ Pledge for Nature, alongside leaders from 64 countries ranging from Bhutan and Pakistan to Canada and Mexico, and the EU.

Under the pledge, countries agree to prioritise a green recovery from coronavirus, deliver ambitious biodiversity targets and increase financing for nature, among other commitments.

The move comes after the UN revealed that the world had failed to meet any of a series of goals agreed a decade ago to halt and reverse declines in biodiversity, the plants, animals and other organisms on Earth, by the deadline of 2020.

UN scientists have warned that nature is in steep decline, with a million species at risk of extinction, while a recent report from WWF revealed wildlife populations have fallen by 68% on average since 1970.

And while conservationists welcomed the move to protect more land at home, they warned that much of the existing 26% of England that is protected is areas such as national parks which do not necessarily deliver for nature.

In his virtual address to the event, Mr Johnson said the UK was taking action at home and on the international stage, and said the pledge for nature “can be only the beginning – just one step on a journey of many miles”.

He said: “We must turn these words into action and use them to build momentum, so that we agree ambitious goals and binding targets, and make the changes we need.

“In short, we need not just good intentions but real action and we must act right now.

“We cannot afford dither and delay because biodiversity loss is happening today and it is happening at a frightening rate.

“Left unchecked, the consequences will be catastrophic for us all. When a species is gone, it is gone.

“Extinction is forever – so our action must be immediate.”

Rosie Hails, director of nature and science at the National Trust, said the announcement to create new habitat could be a significant boost for nature.

“Of course these new areas will need proper management to help nature’s recovery if they are to be more than lines drawn on a map.

“We know that even in some areas already protected for nature such as our national parks, areas of outstanding national beauty (AONB) and many sites of special scientific interest that nature often isn’t doing well – and these are supposed to be the jewels in the crown for biodiversity.”

The National Trust urged the Government to set out how national parks and AONBs will be supported to better deliver for nature, create legally-binding targets for nature through the Environment Bill and deliver a well-funded new agricultural system that rewards environmental outcomes.

Martin Harper, the RSPB’s director of global conservation, said the 30% commitment, if done right, would be a “huge step towards addressing the crisis our wildlife is facing.

“However, targets on paper won’t be enough.

“Those set a decade ago failed because they weren’t backed up by action.

“This is why the 30 by 30 promise must now be put into domestic law, as part of a suite of goals to restore the abundance and diversity of our wildlife, in every country in the UK.”

The Wildlife Trusts said just 10% of land in the UK, 8% in England, was protected for nature through designation as sites of special scientific interest (SSSIs) and many were not in a good condition.

Craig Bennett, chief executive of The Wildlife Trusts said the ambition set out by the Prime Minister was a “good start” but more action was needed on the ground.

“This means rescuing the wildlife sites currently in decline, while also making more space for nature through a new wildlife designation called Wild Belt, specifically aimed at putting nature in recovery, protecting and connecting nature right across the country.”