BERLIN (AP) - Tensions between Germany and Hungary have flared over remarks by the two countries' leaders, including references to Hitler's occupation of the Eastern European country in 1944 and an irritated German government response condemning Hungary's allusion to the Nazi era as a "deplorable derailment" on Monday.

The spat was set off last Thursday, when German Chancellor Angela Merkel said at an event in Berlin that despite concerns over Hungary's democratic deficits, she would not seek to resolve disagreements by "sending cavalry".

"We will do anything to get Hungary onto the right path - but not by sending the cavalry right away," Dr Merkel said at the Europaforum WDR, an annual meeting of politicians, business leaders and journalists. Germany and the European Union have repeatedly expressed concern over Hungary's constitutional changes, which many have condemned as undemocratic.

However, Dr Merkel's mention of the cavalry was first and foremost a domestic reference to the country's opposition party leader Peer Steinbrueck, who is running against Dr Merkel in Germany's general election in September.

Mr Steinbrueck had upset Switzerland in 2009 at the same event when he called for governments to use "the whip" against Switzerland's "tax havens" and said the alpine nation faced the threat of the "cavalry".

Hungarian Prime Minister Viktor Orban responded to Dr Merkel's "cavalry" remarks a day later by referring to German tanks that invaded Hungary during World War II in 1944.

"The Germans have already sent cavalry to Hungary - they came in form of tanks. Our request is that they don't send any. It didn't work out," Mr Orban told state broadcaster Kossuth Radio.

This comment and a report on Spiegel Online headlined "Orban accuses Merkel of using Nazi methods" seemingly upset the German government so much that on Monday German Foreign Minister Guido Westerwelle accused Mr Orban in a statement of "a deplorable derailment which we clearly reject".

Earlier last week, Human Rights Watch urged the EU to ensure that Hungary changes its Constitution and other laws to bring them in line with international norms on issues ranging from independence of the judicial system to the rights of the homeless.

Mr Orban's Fidesz party has used its two-thirds majority in the legislature to push through laws, including a new Constitution, which critics say weaken the democratic system of checks and balances on the government's power.