Image caption Mr Karzai said the US and Taliban were in "daily talks"

President Hamid Karzai has issued a stinging rebuke to the US and the Taliban, saying they are both guilty of sowing fears for post-2014 Afghanistan.

He said Taliban suicide attacks on Saturday were aimed at intimidation that would prolong the presence of international troops in Afghanistan.

The troops are scheduled to end combat missions in 2014.

Mr Karzai has cancelled a scheduled press conference with visiting US Defence Secretary Chuck Hagel.

A senior Afghan presidential aide told the BBC this was because of tensions over civilian casualties, the handover of control of Bagram prison and the actions of US Special Forces in Wardak province.

US officials said it was because of security concerns and not the president's recent comments.

Taliban denial

In a nationally televised speech, President Karzai referred to two Taliban attacks on Saturday in Khost and Kabul that left 19 people dead.

He suggested both the US and Taliban were trying to convince Afghans the situation would worsen after 2014.

He said: "Yesterday's bombings in the name of the Taliban were aimed at serving the foreigners and supporting the presence of the foreigners in Afghanistan and keeping them in Afghanistan by intimidating us."

Image caption Chuck Hagel is currently on his first visit to Afghanistan as US defence secretary

Responding to Mr Karzai's speech, US and Nato forces commander Gen Joseph Dunford said: "We have fought too hard over the past 12 years, we have shed too much blood over the last 12 years, to ever think that violence or instability would be to our advantage."

The BBC's Quentin Sommerville in Kabul says relations between Mr Karzai and the US are in bad shape, with the president angry that the US has not transferred Afghan prisoners held in US custody at Bagram prison.

The Afghan government also accused US-led forces and Afghans working with them of abusing and arresting university students, in violation of national sovereignty.

Analysis Chuck Hagel's first trip abroad has been far from flawless, and that is not a reflection on the new head of the Pentagon. What do you say over dinner to a man who accused your government of nefarious dealings with the Taliban on live television earlier that day? US officials said that because of security concerns, the news conference at the presidential palace had to be cancelled. That might well be the truth, but whispers in Kabul say Mr Karzai called it off to show he is angry. It was not safe enough for Mr Hagel to visit his counterpart's office at the defence ministry, which was attacked by a suicide bomber on Saturday. Afghanistan is a war zone, granted, but that this is the state of affairs is disconcerting to say the least. If Mr Karzai continues to push away countries like the US and Pakistan, he may well end up feeling friendless well before the 2014 deadline.

Mr Karzai also said that "Taliban leaders and representatives are talking with the US abroad every day".

Our correspondent says the president would rather the insurgents spoke to him, but they will not do so as they regard his government as illegitimate.

A statement from the US embassy in Kabul said Washington had "long supported an Afghan-led process for Afghans to talk to Afghans".

But it pointed out that the Taliban had suspended talks with the US in March 2012 and it was "up to the Taliban to take the next steps".

A Taliban spokesman denied the group was holding any dialogue with the US.

Mr Karzai's speech comes as Mr Hagel makes his first visit to Afghanistan.

The two governments are still negotiating a deal on the long-term presence of US forces in Afghanistan.

Mr Karzai said any force that remained "must respect the national sovereignty of our country and must respect all our customs".

There are about 66,000 US military personal at present in the country. Early next year that figure will drop to 34,000. The number of international troops that will remain after 2014 is still to be determined.