Bush, currently on a "farewell" tour of Europe, is seeking to build-up European support for new sanctions if Iran remains defiant.
Iraq war opposition
White House officials said Iran's "defiance" over its nuclear programme was likely to figure prominently during Monday's talks.
With much opposition across Europe to the US-led war in Iraq, Bush has spent a lot of his week-long trip building opposition to Iran's uranium enrichment activities.
Washington says the work could be employed to build nuclear bombs, despite a National Intelligence Estimate by 16 US intelligence agencies in December saying Tehran is believed to have stopped trying to build nuclear weapons in 2003.
Mohamed ElBaradei, the head of the UN nuclear watchdog, has said the NIE were conclusions were similar to his agency's findings.
Bush and Brown are expected to tread a cautious line over the Iraq war, unpopular in both their countries and a source of deep anti-Bush sentiment in Britain and Europe.
Up to 2,500 demonstrators in Britain protested against Bush's visit, police said.
|It is the first time Brown is hosting |
Bush on home soil [AFP]
Police in riot gear created a buffer to allow Bush's motorcade to reach Brown's Downing Street residence for dinner.
Several demonstrators were injured in scuffles with police and authorities said they arrested 25 people after demonstrators pelted officers with placards as they tried to breach a police cordon set up near the prime minister's Downing Street residence.
The rally in London's Parliament Square on Sunday was held 300m from Downing Street where Bush was dining with Gordon Brown, the British prime minister.
Protesters called Bush a "terrorist" and voiced their opposition to the so-called "war on terror".
Police officers were seen beating protesters with batons.
Bush is on what is expected to be his final European tour as US president before he steps down in January.
"This is also a signal to the incoming president that the people of this country are absolutely against this illegal war and destroying civil liberties," said Sarah Cox, a 71-year-old retired teacher who carried a Bush effigy bearing a cowboy hat, toy pistol, and miniature missile.
Security was tight with London's Metropolitan Police saying they had deployed about 1,200 officers to secure the president's 24-hour visit to Britain.
Bush-Brown talks will also include climate change, the state of the global economy and ongoing efforts to agree an international "trade liberalisation" deal.
Bush is scheduled to head to Northern Ireland later on Monday, his last stop before flying home.