BRUSSELS (Reuters) - The European Union could consider aggregating its member countries' demand to buy U.S. liquefied natural gas, as part of negotiations with President Donald Trump to try to avert a trade war, Lithuania's energy minister told Reuters on Tuesday.

When EU ministers met on Monday to consider the bloc's response to Trump's planned 20% tariffs on most EU goods, EU trade commissioner Maros Sefcovic said LNG could be part of negotiations.

Also on Monday, Trump said the EU would need to buy U.S. energy and that could reduce the U.S. trade deficit with the bloc.

The U.S. is already Europe's largest LNG supplier, providing 45% of EU LNG imports last year.

Zygimantas Vaiciunas said the EU's options to incentivise purchases of U.S. LNG included "demand aggregation", in which the European Commission would collate LNG demand from groups of EU countries or the entire bloc to present a bigger request for supplies.

"I think that would be one of the potential future talks, about the demand and the potential managing of the demand in the regions, or in the entire EU," Vaiciunas said.

The EU does not directly purchase gas, which is done by companies and traders in commercial contracts. But Brussels has run a joint gas buying scheme, aimed at increasing the bargaining power of member states, since 2023.

While individual companies sign the final contracts, the EU scheme gathers European companies' demand and matches it with offers from global gas sellers.

U.S. LNG has become more crucial to the EU since Moscow's invasion of Ukraine, which forced Europe to reduce its dependence on Russian pipeline gas.

Ukraine is also looking to import large volumes of U.S. gas this year via terminals in countries including, Germany, Poland and Lithuania, a senior Ukrainian energy official told Reuters last month.

Vaiciunas said the EU could also consider amending its methane emissions rules that some U.S. companies say they will struggle to comply with.

"There are some new regulations which have some additional thresholds for U.S. LNG to enter the European market. So this is one of the potentials that could be changed," Vaiciunas said, referring to the EU methane law.

He said the European Commission has not started talks with EU governments on the details of how LNG could factor into trade negotiations with the U.S.

Starting this year, the EU obliges importers of oil and gas to report the methane emissions associated with those imports. Some U.S. LNG exporters have said the fragmented nature of the country's gas industry means they cannot track emissions along their value chains, down to the fields that gas is extracted from.