OTTAWA -- Public Safety Minister Ralph Goodale is defending the federal response to flood relief efforts in Ontario and Quebec, saying the Liberals sent troops and resources immediately after hearing provincial pleas for help.

Goodale said the federal government agreed to send military personnel to Quebec "within 30 seconds" of that province asking for help Friday and is now moving 250,000 sandbags into flooded communities around Ottawa after complaints about running out arose on Sunday night.

Goodale said the federal government couldn't send in help on its own -- local and provincial officials had to ask first.

That process of responding to a natural disaster will go under review when Goodale meets his provincial and territorial counterparts at the end of the month. Goodale said one jurisdiction or government cannot alone be responsible for responding to a natural disaster.

"These kinds of disasters cannot be pigeon-holed," he said. "It takes a collaborative, all-in kind of approach. That's the best way to protect peoples' lives and livelihoods."

Goodale said every level of government is pulling together to keep people safe in what he describes as a very serious situation.

Some 1,650 members of the military are in, or on their way to flood-ravaged zones of Quebec as part of federal efforts to help communities affected by rising waters.

The minister said the government is reaching out to private sector suppliers to find up to four million sandbags, if required, to help protect homes and critical infrastructure from flood waters. He said the government will look to local suppliers first before deciding whether to transport bags from elsewhere in the country.

The federal government annually sets aside money in its budget to help pay for natural disasters. This year, government spending documents show the Liberals have budgeted $679.3 million, a drop from the $848 million budgeted last year.

The money won't cover the total disaster relief costs. Goodale said federal and provincial officials would negotiate which level of government will pick up what costs once the final bill is tallied.

"We'll sort that out in the days ahead and we'll do so fairly that is appropriate in the circumstances, but the key thing is make sure the resources are there to keep people safe," he said.

The Liberals came under pressure in the House of Commons on Monday from the opposition New Democrats to ensure that federal help will remain in place after the flood waters subside. NDP MP Matthew Dube, whose Quebec riding of Beloeil-Chambly experienced flooding in 2011, said flood-ravaged areas will need the military to help clean up all the sandbags troops are helping to put down and local residents will need financial help rebuilding their homes and their lives.

"What's critical is not just what's done while it's going on, but also what happens after, when the cameras are turned elsewhere, so we hope that the government will continue to provide that help," Dube said.

Goodale said the government plans to assist with cleanup efforts in affected communities.