WASHINGTON - US Secretary of State Mike Pompeo and his British counterpart discussed on Thursday bilateral ties and key global priorities, the State Department said in a statement.

The pair talked about "countering Iranian malign behavior and next steps on the political process in Yemen," according to State Department Deputy Spokesperson Robert Palladino.

They also discussed next steps on "encouraging Russia to return to full and verifiable compliance" of the Intermediate-Range Nuclear Forces (INF) Treaty, said Palladino.

The top US and British diplomats reaffirmed the special relationship between the two countries, saying it yielded "unparalleled cooperation," the statement added.

The two close allies, however, have been struggling to agree on how to deal with Iran.

The United States and Poland will jointly host an international ministerial conference on the issue in Warsaw next month, which is widely believed to further isolate Iran.

Citing European diplomats, some US media reported that Britain had not decided yet whether to send its foreign secretary or other representative to the Warsaw meeting.

Last November, Hunt and his counterparts in France and Germany expressed their dissatisfaction with the US decision to re-impose sanctions on Iran. Hunt visited Iran later that month, the first Western foreign minister to do so after the US withdrawal from the Iran nuclear deal.