Pakistan on Sunday hit back at the United States State Department for suggesting Islamabad needed to do more to hold Lashkar-e-Taiba (LeT) leader Zakiur Rehman Lakhvi accountable, instead asking Washington to "reserve its concern" for the financing and execution of terror activities by India.

The Foreign Office (FO) rejoinder on Twitter came in response to a statement issued by the US State Department's Bureau of South and Central Asian Affairs after the conviction of Lakhvi, a key leader of the banned LeT, on a charge of terror financing by a Lahore anti-terrorism court.

The statement said although the US was "encouraged" by Lakhvi's recent conviction, his alleged crimes "go far beyond financing terrorism".

"Pakistan should further hold him accountable for his involvement in terrorist attacks, including the Mumbai attacks," the State Department added.

In response, the FO stated that Pakistan was "fully abiding by its own statutes and fulfilment of its international obligations".

"The investigations, prosecutions and subsequent convictions, through due process, are a reflection of the effectiveness of Pakistan’s legal system which operates independent of any extraneous factors or influences," it stressed in a tweet.

The FO statement emphasised that the legal process in the ‘Mumbai Case’ remained stalled due to the "reluctance by [the] Indian side to send witnesses for cross-examination by [the] Pakistani court".

"The State Department is encouraged to reserve its concern for the active aiding, abetting, planning, promoting, financing & execution of terrorist activities by India for which sufficient irrefutable evidence has already been provided," it added.

A day earlier, the FO had also rejected a "malicious" statement issued by the Indian Ministry of External Affairs (MEA) regarding Lakhvi's conviction, saying it was “unfortunate” that India was linking Pakistan's due legal process with the Financial Action Task Force (FATF) review.

India had questioned the timing of action against Lakhvi. According to India Today, the MEA said that UN proscribed entities and designated terrorists “act as proxies for Pakistan's establishment to fulfil Islamabad's anti-India agenda”, adding that the action to convict Lakhvi was taken by Pakistan at this time to project a "sense of compliance" ahead of the upcoming FATF meet.

Lakhvi convicted of terror financing

On January 2, Lakhvi was arrested in Lahore in an intelligence-based operation. He was running a medical dispensary to collect and disburse funds for financing terrorism, a CTD spokesman had said, adding that a case of terrorism financing was registered.

On Friday, a Lahore ATC sentenced Lakhvi to five years' imprisonment each on three separate charges, to be served concurrently, and a fine of Rs300,000. The court also directed law enforcement agencies to arrest the co-accused in the case, Abu Anas Mohsin, due to availability of sufficient evidence against him.

The court also handed over possession of the dispensary to the state.

As leader of the proscribed militant group LeT, Lakhvi is blamed by the US and India for the 2008 Mumbai attacks. He was first arrested in 2008 but was later released on bail.

India has long called on Pakistan to bring Lakhvi to trial, but Islamabad says Delhi has not provided concrete evidence to try the LeT leader.

A UN Security Council sanctions committee says Lakhvi is LeT's chief of operations and accuses him of being involved in militant activity in a number of other regions and countries, including Chechnya, Bosnia, Iraq and Afghanistan.