Canadian officials have announced that they will expand a resettlement program to take in about 20,000 Afghan refugees.

Immigration Minister Marco Mendicino told reporters the country was "showing tangible leadership" with the scheme, which will focus on those who are "particularly vulnerable" including human rights activists and women leaders.

"The situation in Afghanistan is heartbreaking and Canada will not stand idly by,” Mr Mendicino said at a press conference.

Appearing alongside him, Foreign Minister Marc Garneau said protecting the Canadian embassy staff in Kabul was a "top priority".

In his short speech, President Ashraf Ghani said the remobilisation of Afghanistan's armed forces are a "top priority", and he is holding consutations with local leaders and international partners on developments in the country.

President Ashraf Ghani is expected to give a public address within the next few minutes.

We will bring you the latest as it comes in.

Image source, Getty Images

The US says an evacuation force of 3,000 troops has begun arriving in Afghanistan, and most will have touched down by the end of the weekend.

America intends to airlift thousands of people a day out of Kabul, including most of the staff at its embassy in Kabul.

Meanwhile the UK, which is sending 600 troops to aid the evacuation of British nationals and former Afghan staff, has said staffing at its embassy would be reduced to an absolute minimum. Germany plans to do the same.

Denmark and Norway are closing their embassies altogether.

Jonathan Beale
BBC defence correspondent

Image source, EPA

The speed of the Taliban advance in Afghanistan appears to have taken many by surprise.

So how did it unravel so quickly?

The US and its Nato allies - including the UK - have spent the best part of the last 20 years training and equipping the Afghan security forces.

The Afghan government should, in theory, still hold the upper hand with a larger force at its disposal. Afghan security forces number more than 300,000, on paper at least.

But the Afghan army and police have a troubled history of high casualties, desertions and corruption.

Read more here.

The security situation in Afghanistan is causing a humanitarian crisis.

Hundreds of thousands of people have been displaced. Many have fled to the capital Kabul, where they are sleeping on the streets and barely able to access basic needs.

The UN Secretary General, António Guterres has said the situation is spinning out of control, and has appealed to neighbouring countries to keep their borders open to allow people to reach safety.

We will bring you the latest news and reaction on the Taliban’s rapid advance in Afghanistan.

Here are some of the most recent developments:

• The Taliban now control most of northern Afghanistan and half of its regional capitals
• Heavy fighting has broken out in Mara-i-Sharif - the only major city still under government control in the north
• Clashes have also broken out in Maidan Shar, a provincial capital just 40km (25 miles) from the capital Kabul.
• Mohammad Ismail Khan, a militia commander who had been helping to lead the fight against the Taliban, was detained by the Taliban on Friday. They released video footage of him speaking, apparently under duress
• A number of countries have announced plans to evacuate their citizens from the country including the US, UK, Norway and Finland. Meanwhile, France has reiterated calls for its citizens to leave as soon as possible
• United Nations Secretary General Antonio Guterres has warned that “Afghanistan is spinning out of control”.