Islamabad: Afghan President Hamid Karzai sought Pakistan's support on Thursday for advancing the reconciliation process in Afghanistan ahead of a trilateral summit on regional security involving Iran's president.   

But the meeting in Islamabad between Karzai, Pakistani President Asif Ali Zardari and Iranian President Mahmoud Ahmadinejad could be overshadowed by Tehran's mounting tensions with the West.   

Iran has been accused of providing low-level backing to Afghanistan's Taliban insurgency and diplomats and analysts have suggested Tehran could ratchet up this support if it wanted to put serious pressure on U.S. forces in Afghanistan.   

Karzai met with Pakistan Prime Minister Yusuf Raza Gilani and the army and intelligence chiefs and discussed efforts to  seek reconciliation with the Taliban to end the war, now in its eleventh year.   

Pakistan is seen as crucial to efforts to reach a peaceful settlement to the war because of its historical ties to the Afghan Taliban and other insurgent groups.   

"The Afghan president termed Pakistan's support as critical to the success of Afghan-owned and Afghan-led peace process and the reconciliation in the country," Gilani's office said in a statement after his talks with Karzai.   

As part of his bid to push reconciliation, Karzai is expected to meet Pakistani opposition politicians and religious leaders, Afghan officials said.   

They include Maulana Sami-ul-Haq, head of a Pakistani seminary said to have been attended by senior Afghan Taliban leaders. He is known as "the father of the Taliban".   

Eyes on Iran    

But the world is currently focused on Iran's standoff with the West.   
Iran has proposed a resumption of long-stalled nuclear talks with world powers in which Tehran would have "new initiatives", according to a letter from Tehran to European Union foreign policy chief Catherine Ashton on Thursday.     

The brief letter, which offered no specific proposals in the nuclear dispute, may not convince Western states that Iran is ready to enter the kind of substantive negotiations tackling its nuclear work they say is needed to resolve the longstanding row.

Tehran on Wednesday proclaimed advances in nuclear know-how, including new centrifuges able to enrich uranium much faster, a move that may heighten its confrontation with the West over suspicions it is seeking the means to make atomic bombs.   

Iran's resolve to pursue a nuclear programme has showed no sign of wavering despite Western sanctions inflicting increasing damage on its oil-based economy.   

Israeli Defence Minister Ehud Barak called for more pressure.    

"(Iran's nuclear armament) is unacceptable ... We're determined to prevent it and not to move any options off the table," he told Japanese public broadcaster NHK. "When we say it, we mean it."    

Tension between Iran and the West has mounted since November, when the U.N. International Atomic Energy Agency said Tehran appeared to have worked on designing a nuclear weapon.      

Widely believed to be the Middle East's only atomic power, Israel has said a nuclear-armed Iran would be a threat to its existence. Both Washington and Israel have not ruled out military action to stop Tehran developing atomic bombs.     

Israel accused Iran and its Lebanese militant ally Hezbollah of being behind twin bomb attacks that targeted Israeli embassy staff in India and Georgia on Monday. Tehran has denied involvement in the attacks.    

Thai investigators said on Wednesday they believe they have found a link between the New Delhi bombing and one in Bangkok on Tuesday.