Angela Dorothea Merkel is a German politician serving as Chancellor of Germany since 2005. She served as the leader of the centre-right Christian Democratic Union from 2000 to 2018.
Soleimani was killed in a U.S. drone strike in Iraq on Friday on the orders of President Donald Trump .
European leaders called on all sides to show restraint.
Meanwhile, US Secretary of defense Mark Esper has suggested, according to a letter from a U.S. general there, a retreat.
Earlier, Boris Johnson said the Prime Minister of Iraq Adel Abdul Mahdi, by phone, and a Downing Street spokesman said the leaders had agreed "to work together to find a diplomatic way in the future".
"The Prime Minister underlined the British determination not to give up Iraq to the stability and sovereignty, and stressed the importance of the continuous fight against the common threat posed by Daesh [the Islamic state group]".
After that, foreign Minister Dominic Raab said the government is the Central message was "the importance of de-escalation of tensions and the search for a diplomatic way through this crisis".
He also distanced himself from the UK to the US President, the threat, the cultural sites can be addressed in Iran specifically, saying: "We have been clear that cultural sites are protected under the International Law , and we would expect them to be respected. "
About 400 British troops are in Iraq, while the US is around 5,200 has.
Nato Secretary-General Jens Stoltenberg announced on Monday that The Alliance armed forces had suspended the training in Iraq. Only a small number of British troops in Iraq are involved in the operation.
The army says that British troops are in the country to Iraqi and Kurdish security forces - rather than in a combat operation and More Than 25,000 Iraq have formed forces.
caretaker Prime Minister of Iraq Mr Abdul Mahdi, spoke in favor of U.S. and other foreign troops leave the country, although most of the Sunni and Kurdish deputies boycotted the vote.
A UK government spokesman said the coalition troops were in Iraq to protect its people and others of the Islamic state group, at The Request of the Iraqi government.
Meanwhile, Iran's Ambassador to the UK has vehemently denied that his country had threatened to kill British troops after The Assassination of Soleimani.
The Paper quoted an unnamed senior commander in Iran's revolutionary guards with the words, his troops would "target US troops in the Middle East , without any worry about the kill, its allies, including the British troops".
"I'm going to ask you to, the relevant UK authorities to act quickly to stop malicious false propaganda in this very sensitive time," he said.
An Iranian Embassy official told the BBC there were no plans to attack British targets and said any suggestion that an attack could take place, which in the UK is ridiculous, adding: "we are not idiots".
the Retired Army Officer Sir Simon Vincent Mayall warned on Radio 4 's Today programme that British troops could be killed serving in the Middle East "possibly" in retaliation to attacks on American soldiers.
the Ministry of defense adviser said, the Western allied troops in neighbouring Iraq were" joined at the hip", and the victim could be divided in Iraq, if Iran fails.
In a joint statement, on Sunday evening, Mr. Johnson, Germany's Angela Merkel and France's Emmanuel Macron , the current cycle of violence said, must be "stopped," and urged Iran to refrain from further violent action, and proliferation.
With rising tensions in the region, Iran has responded by vowing revenge and announces it is the compliance with the restrictions in 2015 the nuclear deal is.
The offer is limited Iran's nuclear capabilities in exchange for the lifting of economic sanctions.
A No 10 spokesman said Iran's announcement was "very".
"We have always said that the nuclear deal is a mutual offer and in terms of Iran's announcement, we said urgently Partner talk about the next steps", the spokesman.
in their statement, the three European heads of government asked the country to "reverse all measures which are incompatible with" The Deal .
Mr Johnson said he spoke with President Trump on Sunday about The Assassination of the Iranian general, the leader of the country's military operations in the Middle East as head of The Elite Quds Force .
The White house said the two leaders had" reaffirmed the close Alliance between the Two Countries ".
the Following warnings from Iran, Mr Trump said that the United States would react in the case of the retaliation for Soleimani's death, "perhaps in a disproportionate way".
He repeated a threat for the opponents of Iran's cultural heritage, say, the US would values "can strike very quickly and very hard" if Tehran Americans or the US attacked assets.Mr Johnson accused Soleimani of the "destabilization" of the region
On Monday, the former foreign Secretary of state, Jeremy Hunt , told Bbc Breakfast a "heartbreaking" result of The Crisis was to secure that it is now "significantly more difficult" for the release of British-Iranian woman.
she was jailed in Iran for spying-allegations that she denies.
Meanwhile, a British frigate, and Destroyer - Hms Montrose and Hms Defender , at the beginning accompanying the UK-flagged vessels through the Strait of Hormuz in The Gulf , where a tanker was seized by Iran last July .