LONDON  European officials, increasingly concerned that the Continent’s debt crisis will spread, are warning that any new rescue plans may need to cover Portugal as well as Ireland to contain the problem they tried to resolve six months ago.

Any such plan would have to be preceded by a formal request for assistance from each country before it would be put in place. And for months now, Ireland has insisted that it has enough funds to keep it going until spring. Portugal says it, too, needs no help and emphasizes that it is in a stronger position than Ireland.

While some important details are different, the current situation feels eerily similar to what happened months ago in Greece, where the cost of borrowing rose precipitously.

European authorities stepped in with a rescue package, expecting an economic recovery and the creation of new European rescue funds to fend off future panics by bond investors whose money is needed by countries to refinance their debt.