US President Barack Obama has engaged in an unprecedented¹ written exchange with a blogger in Cuba who is openly critical of its communist government.

美国总统奥巴马与古巴公开批评其共产主义政府的某博客作者展开空前的书面交谈。

President Obama's reply was posted on the dissident Cuban's blog

His comments came after prize-winning blogger Yoani Sanchez sent questions chiefly about US-Cuba relations.

Mr Obama said in one of the responses he wanted better ties, but indicated it was up to Cuba to act.

Ms Sanchez, 34, has also sent questions to Cuban President Raul Castro, but has not received a reply so far.

The White House confirmed the US president had written to Ms Sanchez.

Asked if he was prepared to hold direct talks with Cuba, the US president said he was not interested in "talking for the sake of（为了……的利益） talking".

He said he wanted "direct diplomacy²（外交）" with Cuba.

"The United States has no intention of using military force in Cuba... Only the Cuban people can bring about positive change in Cuba and it is our hope that they will soon be able to exercise their full potential."

'Repressive system'

Ms Sanchez's Generation Y blog on the trials and tribulations³ of everyday Cuban life has won several major international journalism⁴ awards.

But the BBC's Michael Voss in Havana says that recently, her postings appear to have become more political.

Last week she claimed she had been briefly⁵ detained（扣押） and beaten by members of the state security forces, which prompted a letter of concern from the US state department.

In a report released this week, Human Rights Watch accused President Raul Castro of perpetuating⁶（使不朽） the repressive system of his brother Fidel.

The report said the authorities relied on a law which allows the state to jail people even before they commit a crime.

It documented more than 40 cases where individuals had been jailed for "dangerousness" for such activities as staging peaceful protests or organising independent trade unions.