By Jon Leyne BBC State Department correspondent

As a possible war with Iraq approaches, President Bush has some pressing concerns to raise with Ariel Sharon as he visits Washington.

Mr Bush is keen to keep Israel from retaliating if it is attacked by Iraq.

The US is worried that an upsurge in conflict in the West Bank and Gaza could make it more difficult to win allies in the Arab world for a war on Iraq

And the US president will also quietly urge the Israelis not to enflame the situation with the Palestinians.

The Bush administration applied discreet pressure with a letter it sent to the Israeli Government before the weekend.

Washington made a rare criticism of Israel for recent civilian casualties amongst the Palestinians and for maintaining restrictions on the Palestinian people.

The Bush administration does not want the Israeli-Palestinian conflict to spiral out of control ahead of possible military action against Iraq.

Friendly advice

The United States is worried that an upsurge in conflict in the West Bank and Gaza could make it more difficult to win allies in the Arab world for a war on Iraq.

Bush is focusing on Iraq

And with the US midterm elections just weeks away, President Bush wants to keep the Israeli-Palestinian conflict on hold.

Mr Bush does not want to be seen arm-twisting Israel to show restraint with the Palestinians.

It would not play well with Mr Bush's Republican base, and the party is keen to regain control of both houses of Congress.

The last elections left the Senate split 50/50 between Republicans and Democrats, but a defection by Vermont Senator Jim Jeffords gave control of the Senate to the Democrats.

Mr Bush's domestic agenda has been stalled.

The US is unlikely to make any big push for peace in the Middle East before military action Iraq.

And President Bush will use Mr Sharon's visit to address issues that might arise if the US does attack Iraq.

Iraq assurances

The United States has not received the assurance that it would like that Israel will stay out of any war with Iraq, even if attacked.

Mr Bush is likely to engage in serious arm-twisting on this point and will most likely get the kind of commitments he wants.

Iraq still has Scud missiles

Israel is even more able to defend itself than in the 1991 Gulf War with an improved missile defence system.

The Arrow missile is the world's first purpose-built, operational anti-ballistic missile, and the Israelis hope it will defeat any Scud missiles launched by Iraq.

Iraq fired 39 Scuds at Israel during the 1991 Gulf War.

Those missiles had conventional warheads, but the concern is that this time, Saddam Hussein will top his missiles with poison tips, carrying chemical or biological payloads.

The Arrow missile has performed well in tests, but its ultimate test may come if the US attacks Iraq to disarm or oust Saddam Hussein.

For his part, Ariel Sharon is concerned that Palestinian groups might see the next few months as an opportunity to launch attacks with less fear of retaliation.

As for the Palestinians, they are terrified that Ariel Sharon would use the cover of a wider war, to launch new, more aggressive military action in the West Bank and Gaza.