Australian retail property group Westfield Group (ASX: WDC) says it is confident of strong performance across its portfolio this calendar year despite the impact of a lower U.S. dollar.

This comes after Westfield on Tuesday confirmed operational earnings guidance of $1.7 billion for 2011 compared with $2.06 billion reported in calendar 2010.

Westfield stuck to its annual profit guidance as the negative impact of a strong Australian dollar on offshore earnings is offset by lower interest rates in the US.

There is "definitely a recovery in process" in the U.S., Westfield Joint Chief Executive Peter Lowy told reporters. "The retail industry is recovering, the economy is recovering," he said.

He also said London was "powering ahead" and he expected the mixed economic situation in Australia to improve.

"Some parts of the (Australian) economy are not as well off as the others, but I think in the foreseeable future it will balance itself out because our economy is very strong, very robust," Mr Lowy said.

The Australian mall operator said sales from Australian specialty stores rose 4.4 per cent in March and April compared to the same two-month period a year earlier. In New Zealand they were up 3.6 per cent. They jumped 7 per cent in the US.

By 1511 AEST, shares in Westfield were trading up 0.2 percent at A$9.05, outperforming a 0.7 percent fall in the benchmark index.