US President George W Bush is in Germany on the latest leg of what is likely to be his last tour of Europe, reported BBC.
His talks with Chancellor Angela Merkel are expected to focus on Afghanistan, Iran and the Middle East peace process.
Earlier, Mr Bush attended a summit with EU leaders in Slovenia where they threatened Iran with further sanctions unless it suspended nuclear enrichment.
He said an Iran with a nuclear weapon would be "incredibly dangerous" to world peace.
Mr Bush will later travel to Italy, France and the UK on what is being seen as an eight-day farewell tour of Europe.
During the trip, Mr Bush has held out the prospect of a global deal on combating climate change, which he said could be achieved by the end of his term in office in January.
The US president and his European hosts ended the summit by admiring a show of Slovenia's dancing Lipizzaner horses - a fitting image the BBC's Oana Lungescu at the summit said - as it suggests the days of cowboy diplomacy are over and, after the strains of the Iraq war, Europe and the US seem back in step again.
Whatever divides the US and Europe, our correspondent adds, they remain the world's inevitable partners, united not just by history and values, but also daily trade worth $3bn.
As well as issuing its warning on Iran, the leaders at the Slovenia summit discussed the crisis in Zimbabwe, urging the UN to send monitors to the country to check on its human rights situation ahead of the 27 June presidential run-off
They also called for urgent progress in talks for a world trade deal, which European Commission President Jose Manuel Barroso said would be good for developing countries.
A joint EU-US statement issued after the Slovenia summit urged Tehran not to continue defying a demand from the UN Security Council to stop the enrichment of uranium as part of its nuclear programme.
The 5,000 word statement said "additional measures" would include "steps to ensure Iranian banks cannot... support proliferation and terrorism".
"We will fully and effectively implement" the existing UN sanctions "and we are ready to supplement those sanctions with additional measures," said the statement.
"We will continue to work together... to take steps to ensure Iranian banks cannot abuse the international banking system to support proliferation and terrorism."
The UN Security Council has approved three rounds of sanctions against Iran. These include asset restrictions and travel bans on Iranian individuals and companies said to be involved in nuclear work.
The sanctions also ban the sale to Iran of so-called dual-use items, which can have either a military or civilian purpose.
Correspondents say Washington is now attempting to apply pressure on individual European businesses to take a harder line on Iran.
Barclays Bank, based in the UK, has already responded to such pressure and ended all dealings with Iran's Saderat Bank and Bank Melli, which are on the US list of Specially Designated Nationals.
All US businesses trading with anyone on the SDN list must block their accounts immediately and end any business involvement.
Tehran meanwhile has told Iranian banks to transfer assets and investments from European banks to Iran's central bank.
Observers say the move is not only to escape economic sanctions, but also part of a wider government plan to create a huge pan-Iranian bank run on Islamic principles.
EU foreign policy chief Javier Solana will go to Iran on Sunday with a "refreshed" offer of economic and political incentives.
"Now's the time for there to be strong diplomacy," said Mr Bush during the joint press conference.