Pakistan Prime Minister Nawaz Sharif has reportedly contacted Russia, South Korea and New Zealand to gain support for NSG membership.
The government has been maintaining its diplomatic push in event of USA backing rival India's bid to join the 48 nation club of nuclear trading countries.
On 8 June, Pakistan Prime Minister Nawaz Sharif's adviser on foreign affairs Sartaj Aziz had a telephonic conversation with the foreign ministers of Russia, South Korea and New Zealand in order to gain support for the country's application for NSG membership, Express Tribune reported.
Pakistan Ministry of Foreign Affairs spokesperson Tasnim Aslam at a detailed briefing for diplomatic missions of the NSG countries in Islamabad highlighted the factors, which placed Islamabad's application for a NSG membership on solid grounds, including country's technical experience, capability and well-established commitment to non-proliferation and nuclear safety and security.
In a letter addressed to NSG chairman Rafael Grossi on 19 May, Pakistan's Ambassador to Austria, Ayesha Riyaz, said the decision to seek membership in the group reflected Islamabad's support for international efforts aimed at preventing the proliferation of weapons of mass destruction.
"Pakistan has the expertise, manpower, infrastructure and ability to supply NSG-controlled items, goods and services for a full range of nuclear applications for peaceful uses," the letter read while urging the NSG to adopt a non-discriminatory criteria-based approach for group membership.
Islamabad sought a membership of the exclusive nuclear trading club after Indian Prime Minister Narendra Modi secured Washington's backing for New Delhi's bid for a membership.
The support of Mexico and Switzerland is seen as important in the wake of China opposing India's NSG membership arguing that it was not a signatory to the Nuclear Non-Proliferation Treaty (NPT).
The US and many other NSG member countries have supported India's inclusion based on its non-proliferation track record.
The NSG is a 48-nation club dedicated to curbing nuclear arms proliferation by controlling the export and re-transfer of materials that could foster nuclear weapons development.