Afghan President Hamid Karzai has accused the Taliban and the United States of working together to convince Afghans that violence will worsen if most foreign troops leave as planned by the end of next year.

Mr Karzai said two suicide bombings that killed 19 people - one outside the defence ministry and the other near a police checkpoint - show the insurgent group is conducting attacks to help demonstrate that international forces will still be needed to keep the peace after their combat mission ends in 2014.

"The explosions in Kabul and Khost on Saturday showed that they are at the service of America and at the service of this phrase: 2014. They are trying to frighten us into thinking that if the foreigners are not in Afghanistan, we would be facing these sorts of incidents," he said during a nationally televised speech about the state of Afghan women.

There was no immediate response from the US-led military coalition, which is gradually handing over responsibility for securing the country to Afghan forces.

Mr Karzai is known for making incendiary comments in his public speeches, a move that is often attributed to him trying to appeal to those who sympathise with the Taliban or as a way to gain leverage when he feels his international allies are ignoring his country's sovereignty.

In previous speeches he has threatened to join the Taliban and called his Nato allies occupiers who want to plunder Afghanistan's resources.

His latest remarks come as his government is negotiating a pact with the US for the long-term presence of American forces in Afghanistan and days after an agreement to transfer the US prison outside of Kabul to Afghan authority fell through. US defence secretary Chuck Hagel is also making his first visit to Afghanistan since becoming the Pentagon chief.

Mr Karzai said in his speech that any foreign powers that want to keep troops in his country need to do so under conditions set by Afghanistan.

"We will tell them where we need them, and under which conditions. They must respect our laws. They must respect the national sovereignty of our country and must respect all our customs," Mr Karzai said.

Mr Karzai offered no proof of coordination, but said the Taliban and the United States were in "daily negotiations" in various foreign countries and noted that the United States has said it no longer considers the insurgent group its enemy.

PA Media