BRUSSELS (Reuters) -The European Commission said on Friday it saw no justification for U.S. President Donald Trump's proposed "reciprocal" trade policy and would react "firmly and immediately" against tariff increases resulting from it.

The Commission, which coordinates trade policy for the 27-nation European Union, described the proposed policy as a step in the wrong direction. 

"The EU maintains some of the lowest tariffs in the world and sees no justification for increased U.S. tariffs on its exports," the Commission said in a statement.

The European Union's average applied tariff on imported goods was among the lowest globally, the EU executive said, with over 70% of imports entering tariff-free.

A fact sheet from the White House on Thursday highlighted the difference between EU tariffs on car imports of 10%, compared with the 2.5% rate for those entering the United States, as well as EU restrictions on imports of U.S. shellfish.

"The EU will react firmly and immediately against unjustified barriers to free and fair trade, including when tariffs are used to challenge legal and non-discriminatory policies," it said in a statement.

The comments echo European Commission President Ursula von der Leyen's vow on Tuesday of "firm and proportionate countermeasures" in response to Trump's decision to impose tariffs on all steel and aluminium imports.

EU ministers responsible for trade took a softer line on Wednesday by prioritising negotiations over retaliatory measures, aware that the U.S. steel and aluminium tariffs will only apply from March 12.

"There is a window for negotiation," Irish Foreign Minister Simon Harris said in a statement.

Similarly, Trump's directive on Thursday did not impose more tariffs, but instead kicked off what could be weeks or months of investigation into the levies imposed on U.S. goods by other trading partners before devising a response.

Three EU diplomats said it made sense to use the time to negotiate, while preparing a firm response if U.S. tariffs were imposed.