UK's Foreign Secretary Boris Johnson will visit Washington today. Johnson will meet US Vice President Mike Pence, National Security Advisor John Bolton among other Congress leaders.
Johnson will discuss a range of issues at Washinton with the Iran nuclear deal, Syria and North Korea on top of the agenda.
US President Donald Trump described the Iran nuke deal as "insane" and has threatened to pull out of it on its renewal which is due on May 12.
Britain, France and Germany have been trying to keep Trump from abandoning the deal.