TOKYO (Reuters) - Japanese Finance Minister Yoshihiko Noda said on Saturday that it would be hard to compile an emergency budget before the end of March, after a massive earthquake struck Japan the previous day. The quake, the most powerful since Japan started keeping records 140 years ago, sparked a powerful tsunami that struck its northeast coast, probably killing at least 1,300 people and damaging two nuclear reactors. Japan is already the most heavily indebted major economy in the world, meaning any additional borrowing by the government to pay for repairs after the earthquake could be closely scrutinised by financial markets. "We have people working right now on different relief operations," Noda told reporters at a briefing. "Considering that we would have to pull some people from these operations to compile an extra budget, it's unlikely to happen before the end of the fiscal year," which is on the last day of this month. The government could easily use reserves in the budget, but it would take time to estimate the cost of the damage, which is needed to consider the size of an extra budget, Noda also said. When asked what measures the government is considering if Japanese stocks, bonds and the yen are unstable on Monday, Noda said he wanted to monitor financial markets closely. For people living in the most damaged areas, the government will extend indefinitely the March 15 deadline for filing personal income tax returns, Noda also said. Just hours before the quake struck, Prime Minister Naoto Kan was rejecting demands that he resign, his political future looking increasingly bleak and unable even to muster enough support to ensure the passage of bills needed to enact the new budget. But after the tremor, politicians pushed for an emergency budget to fund relief efforts, with Kan urging them to "save the country," Kyodo reported. Noda said that he welcomed opposition parties' willingness to cooperate and that the country had to unite in response to the devastating damage from the earthquake.