Leaders from 47 countries, including the Philippines, will start arriving here Sunday (Monday in Manila) for a two-day summit to talk about the threat of nuclear terrorism. It is the biggest gathering of world leaders in the American capital under the administration of President Barack Obama. President Gloria Macapagal Arroyo is arriving Monday, officials revealed, in time for the start of the summit at the Washington Convention Center in downtown DC. The Philippines will assume the presidency of the Review Conference of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) next month in New York. The treaty, which bounds signatory countries not to spread or allow other countries to spread nuclear weapons, fissile materials and nuclear weapons technology, is reviewed every five years under the auspices of the United Nations. Of the 47 countries joining the summit, 38 will be represented by their heads of state or heads of government, and nine by their vice presidents, deputy prime ministers or foreign and defense ministers. The summit has also drawn nearly a thousand journalists from all over the world. ABS-CBN's North America News Bureau was among the international news organizations accredited to cover the event. RP role vs spread of nuclear weapons Ambassador Libran Cabactulan, a career diplomat who served as Department of Foreign Affairs senior special assistant for nuclear disarmament and non-proliferation, will take over the NPT Review Conference presidency. Cabactulan also replaced former Supreme Court Chief Justice Hilario Davide, Jr. as Philippine Permanent Representative to the United Nations. Observers described the Philippines' role as that of the “honest arbiter” in next month's discussions, which are expected to be dominated by concerns over Iran and North Korea. Iran signed the NPT but is suspected to be trying to build nuclear weapons while North Korea is the only country that has ever pulled out of the NPT. India and Pakistan, which are known to have nuclear weapons, and Israel, which is widely believed to have nuclear weapons but has never acknowledged it, have not signed the NPT. Despite the Philippines' seemingly primal role in nuclear non-proliferation, no meetings are scheduled between Presidents Obama and Arroyo – at least according to the latest White House briefing last Friday. Sunday, President Obama will hold separate bilateral meetings with the leaders of India, Kazakhstan, South Africa and Pakistan, and a courtesy call by President Umaru Yar'Adua of Nigeria. The US Chief Executive will hold another round of sidebar meetings on Monday with King Abdullah of Jordan, Malaysian Prime Minister Mohamed Najib Abdul Razak, President Serzh Sargsian of Armenia, and President Hu Jintao of China. Arroyo to be met with protests Militant Filipino-Americans, meantime, said they will be holding protests near the White House on the eve of Arroyo's arrival. Philippine officials kept a tight lid on the President's schedule in DC. The group “Never Again to Martial Law Coalition” said the Philippine president's participation in the nuclear summit was “political hypocrisy” because of her dismal human rights record. “President Arroyo basks in power with greed and corruption,” their statement read. They cited the arrest of 43 medical workers in Morong, Rizal, the alleged cover-up of the Maguindanao massacre culprits, and the alleged abduction and torture of Fil-Am Melissa Roxas. “Many Filipinos fear that she will not relinquish power by manipulating a failure of elections on May 10, which can be an excuse to declare Martial Law and form a junta with her at the head,” the group declared. The DC police gave them a permit to hold the rally across the White House south lawn. The police is blocking off portions of Pennsylvania Avenue NW, especially near Blair House where President Obama is meeting some world leaders arriving ahead of the summit. Large swaths of downtown DC will be locked down starting Sunday, under a security clamp-down that is being compared with Obama's historic inauguration last year. – ABS