LONDON — Boris Johnson, London’s new mayor, announced a ban on drinking alcohol on all public transportation in the British capital, fulfilling a commitment he made during his election campaign.

The ban, which will come into force on June 1, is intended to make traveling a safer and a more pleasant experience, Mr. Johnson said today in an e-mail statement. Drinking from and carrying open containers of alcohol will be outlawed under amendments to Transport for London’s “conditions of carriage” and the Docklands Light Railway’s “rules for using tickets,” he said.

“I’m determined to improve the safety and security of public transport in London and create a better environment for the millions of Londoners who rely on it,” Mr. Johnson said. “I firmly believe that if we drive out so-called minor crime then we will be able to get a firm grip on more serious crime.”

Mr. Johnson, who defeated two-term Mayor Ken Livingstone in a May 1 election, made improving safety on the city’s streets, buses, and trains a key priority in the campaign.

“This is the first step toward improving safety on the public transport system,” Mr. Johnson told reporters at the London Underground station at Kensington High Street. He’s also planning a “rapid rollout” of 440 additional community support officers to patrol buses, trains, and stations. These officers wear uniforms and support police officers, who have more powers.