US President Barack Obama said Tuesday that Prime Minister Yousuf Raza Gilani's presence at a nuclear security summit in Washington was "a positive sign" and would help to defuse tensions with its India. "Prime Minister Gilani's presence here was an important step in seeing that we do not see a nuclear crisis anywhere in South Asia," Obama said in response to a question at a conference that followed the conclusion of the 47-nation nuclear security summit. Obama also said he was confident that Pakistan's nuclear arsenal was secure, but stressed steps could be taken by every nuclear power to better secure nuclear materials. "Pakistan is not exempt from that, but we aren't either," he said. The India-Pakistan weapons race was not a subject of the two-day summit, but may be considered at the nuclear Non-Proliferation Treaty (NPT) summit in New York in May. Neither India nor Pakistan have signed the NPT. Obama said that he would continue to urge Pakistan and other non-signatories, including Israel, to sign onto the treaty. Obama met bilaterally with Gilani ahead of the summit amid reports by The New York Times that Islamabad is blocking talks on an agreement to stop producing new nuclear material worldwide, and Obama used the Sunday meeting to "express disappointment" over this development. The Times reported that US intelligence officials believe Pakistan is running a new nuclear reactor to produce fuel for a second generation of nuclear weapons - one of three such facilities planned. But Gilani later flatly denied the report. At his press conference, Obama emphasized that he stands for lowering tensions throughout South Asia. "I don't think Pakistan is playing by different set of rules," he declared when asked that Islamabad was playing a different set of rule by expanding its nuclear programme. "I have actually seen progress over the last several years with respect to Pakistan's nuclear security issues. I want to lower tensions throughout South Asia when it comes to nuclear programmes. "The fact that Prime Minister (Yusuf Raza) Gilani came here, signed on to the communique and made a range of commitments that will make it more likely that we don't see proliferation activities or trafficking occuring out of Pakistan, is a positive thing." "Do we have a lot of more work to do ? absolutely. But I think Prime Minister Gilani's presence here was an important step in assuring that we do not see a nuclear crisis anywhere in South Asia." The US leader reiterated Washington's confidence in the safety of Pakistani safeguards. "I feel confident about Pakistan's security arrangement for their nuclear weapons." President Obama opposed the suggestion to single out Pakistan in reply to a pointed question about the South Asian country and stressed it is important that every nuclear state enforces strong measures. "It is important to note that every nuclear power, every country that has a civilian nuclear energy programme, has to take better steps to secure these materials. And Pakistan is not exemption to that. But we are neither," he stated, citing the example of a US air force plane carrying nuclear tipped missiles across the United States. He said Secretary of Defence Robert Gates held those responsible accountable for that mishap.