BRATISLAVA (Reuters) - Central European governments expressed optimism on Friday that the United States remained committed to NATO even though President Donald Trump did not mention the military alliance’s defense commitment set out in its founding treaty this week.

U.S. President Donald Trump delivers remarks at the start of the NATO summit at their new headquarters in Brussels, Belgium, May 25, 2017. REUTERS/Jonathan Ernst

NATO’s founding treaty states under Article V that an attack on one ally is an attack on all, but Trump questioned the principle during the U.S. election campaign and has not publicly backed the commitment.

Speaking on a panel at the GLOBSEC Bratislava Forum in the Slovak capital, the foreign ministers of Slovakia, Hungary and Poland said they had no concerns about the United States’ commitment to NATO.

However, Slovak Foreign Minister Miroslav Lajcak said he would have liked to hear Article V mentioned.

“An optimistic interpretation of his words is that the commitment under Article V is so obvious there was no need to mention it but I still would have preferred if it was mentioned,” Lajcak said.

White House officials said this week Trump stands united with other NATO countries in defending all alliance members.

Hungarian Foreign Minister Peter Szijjarto, who attended meetings of NATO member leaders on Thursday when Trump spoke, said he was confident having heard the U.S. leader speak that the United States would fulfill its obligations and wanted Europeans to do the same.

“What I heard from him yesterday in the meeting made me relaxed,” he said.

The deployment of U.S. troops to Poland and the Baltics have been central to an expansion of NATO’s presence in eastern Europe to levels unprecedented since the Cold War.

The build-up was prompted by Russia’s annexation of Crimea and accusations - denied by Moscow - that it is supporting a separatist conflict in eastern Ukraine.

Poland’s foreign minister, Witold Waszczykowski, said the troop presence was proof of Washington’s commitment.

“It is much better than just a declaratory mention of Article V. I prefer to have 5,000 troops from the United States in Poland. This is a commitment,” he said.