LONDON - British Prime Minister Theresa May said she would talk to U.S. President Donald Trump later on Tuesday about a suspected chemical attack in Syria.

"I'll be continuing to talk with our allies and partners as I have done, speaking to President Macron this morning, and I'll be speaking to President Trump later today," she told reporters in Cambridgeshire in eastern England.

When asked whether Britain would join the United States if Washington decided on further military action in Syria, May declined to answer the question directly but said: "We believe that those responsible should be held to account."

May said she would chair a meeting of Britain's National Security Council later on Tuesday.

"This attack that took place in Douma is a barbaric attack. Obviously we are working urgently with our allies and partners to assess what has happened on the ground," she said.

(Reporting by Sarah Young; editing by Guy Faulconbridge) ((sarah.young@thomsonreuters.com; +44 20 7542 1109; Reuters Messaging: sarah.young.thomsonreuters@reuters.net))