British Prime Minister Theresa May is committed to engaging with the Scottish government on Brexit plans, her spokesman said on Tuesday, a day after First Minister Nicola Sturgeon called for a new independence referendum.

"We have made clear our commitment to engage the Scottish government throughout that process and that commitment remains," the spokesman told reporters.

May's spokesman also said the prime minister had told her top team of ministers earlier on Tuesday that while leaving the European Union is a big project, they must also press on with plans for economic and social reform in Britain.

He also said that May would not attend an EU summit in Rome on March 25, the 60th anniversary of the treaty that laid the bloc's foundation.