SEPANG, March 18 — Even as Malaysia ropes in more countries to help hunt for the missing flight MH370, the operation has become exponentially more difficult with the area now covering over 2.24 million square nautical miles, Datuk Seri Hishammuddin Hussein said today.

The acting transport minister said that the search area is significantly larger than in the first phase of the search and rescue operation — which now measures slightly bigger than the entire land size of Australia — in both the northern and southern corridors investigators have drawn up for the possible location of the Boeing 77-200.

“Malaysia can’t possibly search this enormous area on its own,” he said at the daily press conference here, while welcoming the help of the 24 other countries currently involved in what is possibly the biggest search and rescue operation in the history of aviation.

Hishammuddin explained that the expanded search area covering two possible flight paths in the northern and southern hemisphere that the jumbo jet could have taken, will be split into a total of 14 quadrants, measuring some 160,000 square nautical miles each.

The search in the northern corridor will largely be a land search crossing several countries stretching from Thailand to Kazakhstan, while the southern corridor covers an arc that extends from the southern tip of Sumatra towards the Indian Ocean.

Previously, the search for the Beijing-bound aircraft focused on waters on both sides of Peninsula Malaysia, covering some 224,000 square nautical miles.

This included the Igari sector off Malaysia’s east coast, some 120 nautical miles off Kota Baru, where the plane dropped off the radar, and the Straits of Malacca on the west coast — where it was later determined to have turned back — and further west towards the Andaman Sea.

Hishammuddin, who is also defence minister, stressed that the most immediate need is to narrow the “enormous” search area in both corridors, which requires the consent and cooperation of the various countries within the corridors and also those involved in the search and rescue operation.

“On the logistical front, over the past 24 hours we have been working hard with other countries to narrow the search corridors.

“Our focus is on four tasks: gathering information from satellite surveillance, analysis of surveillance radar data, increasing air and surface assets, and increasing the number of technical and subject matter experts,” he said.

Foreign Minister Datuk Seri Anifah Aman, who was also at the same news conference, said he had sent 12 diplomatic notes to the northern corridor and two to the southern corridor seeking their assistance in the matter.

“This is a very complex situation, as we need to get 25 countries to work as a team. It is a tremendous effort, but the advantage is that Malaysia has cordial ties with all and the prime minister is on a phone call basis with all the premiers and the presidents.

“This would not have been possible if Malaysia did not have good relationships with all the countries involved,” he said.

Hishammuddin said he had also spoken to US Secretary of Defence Chuck Hagel earlier this morning to discuss the possibility of securing US data on the Indian Ocean in the southern corridor.

“In the northern corridor, there are countries that have agreed to lead the search in certain areas,” he added, though he declined to reveal which countries had volunteered their satellite and radar capabilities.

Hishammuddin reiterated that there is no room to speculate over this “unique, unprecedented and complex situation”, as it would only distract the entire search and rescue operation from the main objective of finding the plane.

“That’s why we need to get the black box... we don’t want the team to be distracted. If we can find the aircraft soon, God willing most of the questions raised in the speculation will be answered,” he said.