"So we do wait for the Philippines Government, they have to put out a call for international assistance.
"We're all just waiting to hear really, how it's all going on the ground and whether they will need us."
As well as Mrs Jackson, a water engineer and two technical experts were on stand-by to go to the area.
The situation was "very fluid" at the moment, she said.
"Communications get lost as the storm comes through."
International Oxfam branches were stretched thin at the moment with the Ebola crisis in Africa and the 1.7 million Syrian refugees, Mrs Jackson said.
Last November, the Philippines was hit by Typhoon Haiyan, known locally as Typhoon Yolanda - the largest typhoon ever to hit land.
"These people are already pretty vulnerable," Mrs Jackson said.
The Ministry of Foreign Affairs and Trade said there were 300 New Zealanders registered as being in the Philippines.
"The New Zealand Embassy in Manila has sent a SafeTravel message to all registered New Zealanders warning them of Typhoon Hagupit/Ruby, to follow the advice of the local authorities, and to remain in contact with family members in New Zealand [regarding] their well-being," a ministry spokeswoman said.
The wind strength made Hagupit the most powerful storm to hit the Philippines this year, exceeding a typhoon in July that killed more than 100 people.
"Tin roofs are flying off, trees are falling and there is some flooding," Stephany Uy-Tan, the mayor of Catbalogan, a major city on Samar, told AFP by phone minutes after Hagupit made landfall.
Fearful of a repeat of last year when Haiyan claimed more than 7350 lives, the government undertook a massive evacuation effort ahead of Hagupit that saw millions of people seek shelter.