Islamabad: Pakistan's Ambassador to the US Husain Haqqani on Sunday held an informal meeting with President Asif Ali Zardari to explain his position on a controversial secret memorandum that was purportedly sent by the civilian government to the former US Military Chief.

Haqqani met Zardari hours after he flew into Islamabad on a flight via Qatar shortly after 2 am.

The envoy told Zardari he was ready to face any inquiry into the controversial memo and that he was prepared to cooperate with any authority asked to probe the issue, TV news
channels quoted their sources as saying.

The Ambassador further said he was ready to hand over his Blackberry and its records to authorities, the news channels reported. There was no official word from the presidency on
the meeting. Haqqani is expected to meet Zardari again on Monday.

Earlier in the day, Haqqani left the airport without speaking to the waiting media and reportedly went straight to the presidency.

Haqqani has been at the centre of what the media is referring to as the 'Memogate' controversy since Pakistani- American businessman Mansoor Ijaz claimed last month that a
secret memo delivered to then US military chief Admiral Mike Mullen in May had sought American assistance to prevent a possible military takeover.

Ijaz has claimed that he drafted the memo on the instructions of Haqqani.

The envoy, who offered to resign to help defuse the controversy, has said he played no role in drafting or delivering the memo to Mullen.

Before leaving Washington, Haqqani told the Dawn newspaper that he would appear before a Pakistani parliamentary committee which would be headed by a religious scholar who was also a lawmaker.

He said the panel would hold a full inquiry into the issue and try to "sift facts from fiction".

Haqqani said he would urge the committee to investigate why "the statement of a doubtful individual was blown out of proportion".

He said the enemies of democracy were behind the scandal and wanted to "use it as an excuse to undo democracy".

President Zardari and Prime Minister Yousuf Raza Gilani called Haqqani to Islamabad to explain his position on the controversy following a meeting of the top leadership of the
ruling Pakistan People's Party last week.

Reports have said that the powerful military is pressuring the weak civilian government to remove Haqqani from his post.

Haqqani, a close aide of Zardari, has served as a vital link between the Pakistan government and the Obama administration and played a key role in resolving several
recent crises in bilateral relations, including the stand-off over CIA contractor Raymond Davis, who was arrested after he shot and killed two men in Lahore earlier this year.

However, Haqqani has always had an uneasy relationship with the military for his pro-democracy stance.

Before leaving Washington, Haqqani met US Special Envoy for Pakistan and Afghanistan Marc Grossman.

After the 35-minute meeting, the US State Department issued a statement that said Grossman had never seen the memo before it was made public.

During the meeting, Grossman "referenced the statement of Admiral Mike Mullen's spokesperson that Admiral Mullen did receive a letter from Mansoor Ijaz but that "he did not find it at all credible and took no note of it then or later". Therefore, he addressed it with no one," the statement said.

The State Department stressed the need to continue the democratic process in Pakistan.

"We clearly support the democratically elected government of Pakistan, as well as its constitutional processes," State Department spokesman Mark Toner told a briefing.

At the Pentagon, spokesman George Little told reporters that Defence Secretary Leon Panetta was aware of the issues related to the memo.

However, he said "no review" had been ordered when asked why the serious allegations in the memo were ignored by Mullen's office.