Hours before, an Australian official had been less optimistic, describing the search as looking for a needle in a haystack -- and that they hadn't even located the haystack yet.
No evidence of debris from the plane has been identified or recovered in the search, Australian Defense Minister David Johnston told reporters in Bullsbrook, Australia.
"It's a massive logistical enterprise," Johnston said, and an "amazing example of international cooperation."
"We're not searching for a needle in a haystack. We're still trying to define where the haystack is," added Mark Binskin, vice chief of the Australian Defence Force.
Earlier today, Malaysia Airlines CEO Ahmad Jauhari Yahya also held a news conference in Kuala Lumpur to outline steps the airline is taking for the families, including payments made to them and travel accommodations. The airline has offered family members $5,000 for each passenger aboard Flight 370 and additional payments as the search continues.
"My heart breaks to think of unimaginable pain suffered by all the families," he said.
Malaysia Airlines has come under fire for delivering a text message to families on Monday that stated, in part, "MH370 has been lost and that none of those on board survived."
Responding to the criticism for texting, Yahya said he wanted to make sure the victims' families heard about the news before anyone else.
"Our sole and only motivation last night was to ensure that in the incredibly short amount of time available to us, the families heard the tragic news before the world did," he said.
Today's announcements come after Malaysian Prime Minister Najib Razak said Monday that the plane "ended" its journey in a "remote location" of the southern Indian Ocean.
Razak said officials concluded that the flight had been lost in the deep waters west of Perth based on information from Inmarsat.
Also yesterday, an Australian plane spotted two objects described as gray or green and "circular" as well as orange and "rectangular" in the search area off Australia's coast.
Other search crews had spotted "suspicious objects" in the Indian Ocean over the weekend -- including items believed to be wooden pallets.
Malaysian authorities are considering the possibilities of hijacking, sabotage, terrorism or issues related to the mental health of the pilots.