Islamabad: Pakistan may have low-level participation in the Bonn conference after a telephone call from U.S. President Barack Obama to President Asif Ali Zardari to express condolences over a NATO airstrike that killed 24 soldiers, a newspaper said.

Dawn reported that diplomatic circles in Washington expect low-level participation from Pakistan in the international conference.

Pakistan decided to boycott the Bonn conference to protest the November 26 NATO airstrike that left 24 Pakistan Army soldiers dead in Mohmand Agency. The attack prompted Islamabad to stop NATO supplies through the country and it also decided to stay away from the Bonn conference.

Foreign ministers from over 90 countries are expected to congregate at Bonn for the conference that is going to discuss the future of Afghanistan. Western forces in Afghanistan are scheduled to leave the country by 2014.

Sources said the breakthrough came after U.S. President Barack Obama called up President Asif Ali Zardari.

Obama called Zardari to express condolences, but stopped short of an apology.

"The president made clear that this regrettable incident was not a deliberate attack on Pakistan and reiterated the United States' strong commitment to a full investigation," the White House said in a statement.

"The two presidents reaffirmed their commitment to the U.S.-Pakistan bilateral relationship, which is critical to the security of both nations, and they agreed to stay in close touch."

Earlier efforts to persuade Pakistan to attend the Bonn meet had failed, with Islamabad not heeding requests from countries, including host Germany.

German Chancellor Angela Merkel had telephoned Prime Minister Yousuf Raza Gilani November 30, requesting Pakistan to change its decision.

"The German Chancellor expressed her desire that Pakistan's attendance in the Bonn conference was of utmost importance to Germany and stressed upon that Pakistan's representation was essential for making the conference meaningful," Pakistan prime minister's office had said in a statement.