Peace between Israel and the Palestinians is a "priority," British Foreign Secretary William Hague said on a visit to the region on Thursday, warning that time was running out for a two-state solution.

"The prospects of a two-state solution cannot be kept alive forever as the situation changes," he told reporters from the seat of the Palestinian presidency in the West Bank city Ramallah.

"The two-state solution does not have much longer, there is not much more time in which it could be brought about," he emphasised.

Hague's visit to Ramallah followed a meeting between Abbas and US Secretary of State John Kerry, the fourth visit of the top US diplomat to the region since he took office in February.

Kerry has sought to revive the peace process, which has been stalled since talks between Israel and the Palestinians broke down in September 2010.

Hague said that Britain supported Kerry's efforts, urging him to keep up "momentum."

"We ask the US to make an immense effort... to bring new momentum to the Middle East peace process," he said.

"In the UK and the EU we strongly support (Kerry's efforts)," Hague added.

"We believe that it is essential to bring about a two-state solution .... based on the 1967 borders with agreed land swaps, with Jerusalem as the shared capital of both states, with a fair and agreed settlement for refugees," he said.

Ahead of a meeting with Israeli Prime Minister Benjamin Netanyahu in Jerusalem earlier in the day, Hague had stressed the importance of the "Middle East peace process," which he called "an urgent priority for the United Kingdom and to the world."

In his remarks in Jerusalem, Hague also noted Britain's "very strong concerns" over "the nuclear programme of Iran," which Netanyahu called "the biggest challenge of our time."

"We pursue... sanctions and negotiations, but nobody should doubt our resolve in these matters," Hague said.

The Israeli premier also expressed his condolences for the "horrific terrorist attack against a British citizen in London," a reference to the murder of a soldier in the British capital on Wednesday.

"We sympathise deeply."