British Foreign Secretary Boris Johnson (L) and US Secretary of State John Kerry give a joint press conference after a meeting on the situation in Syria at Lancaster House in London on October 16, 2016. (Photo by AFP)
The United Kingdom and United States say they were considering more sanctions against Syrian President Bashar al-Assad and his supporters, and called on Russia and Iran to help end the 5-year conflict in the country.
"It is vital that we keep that pressure up and there is a lot of measures we're proposing, to do with extra sanctions on the Syrian regime and their supporters," British Foreign Secretary Boris Johnson told reporters on Sunday in London alongside US Secretary of State John Kerry.
"These things will eventually come to bite the perpetrators of these crimes and they should think about it now," said Johnson, who also said there was no appetite in Europe for "going to war" in Syria.
He called on Russia and Iran to show leadership to end the conflict. "It is up to them to show mercy, show mercy to those people in that city and get the ceasefire going.”
Kerry confirmed that Washington and its allies were considering additional sanctions against the Syrian government.
Kerry had traveled to London on Sunday to hold talks with his French, German and British counterparts about the results of his meeting over the Syrian conflict on Saturday in the Swiss city of Lausanne.
The foreign ministers of nine countries attended the Lausanne meeting but failed to agree on a common strategy to end the conflict in Syria.
Several major international efforts have failed to secure a political solution to Syria.
A US- and Russia-brokered ceasefire in Syria ended last month. It had ushered in several days of relative calm, but violence began to creep back when a US-led airstrike killed more than 80 Syrian soldiers.
There are dozens of US special operations forces in Syria, who are working closely with a collection of various militant groups that are trying to topple the country's legitimate government.
The foreign-sponsored conflict in Syria, which started in March 2011, has claimed the lives of more than 400,000 people, according to a UN estimate.