Condoleezza Rice, the US secretary of state on Monday stopped short of threatening a cut in US aid to the Palestinians if they form a government with ministers from the hard-line Islamic movement after parliamentary polls on 25 January.
"Let's just see what happens after the elections," Rice told reporters accompanying her on a visit to Liberia. But she added the US-sponsored peace road map directed at creating a Palestinian state was a "two-way street".
"After these elections, the ability of the Palestinians to engage the Israelis to move forward on the roadmap is obviously going to be dependent on having people in the governing structures who believe in the principles of the roadmap," she said.
"In order to negotiate with a party you have to believe in its right to exist. In order to have freedom of movement and access and peaceful development ... you have to believe that violence is not acceptable."
Israel has opposed any electoral role for Hamas, which refuses to recognise the Jewish state's right to exist, and has been responsible for the bulk of attacks on Israelis since their latest conflict broke out in September 2000.
"In order to have freedom of movement and access and peaceful development ... you have to believe that violence is not acceptable"
US secretary of state
But Rice expressed understanding for the decision by Palestinian leader Mahmoud Abbas to let Hamas run in the legislative elections where they were expected to give his struggling Fatah movement a stiff fight.
"I don't think his (Abbas') programme is really consistent with that of Hamas but I think he is trying to be someone who allows these elections to take place in a free and fair way and I think that is totally appropriate," she said.
She added, however, that any Palestinian government that came out of the elections would have to respect the spirit and provisions of the road map drafted by the United States, European Union, United Nations and Russia.
"The Palestinian government will have to be responsive to certain basic elements in order to make it work," Rice said. "If there is going to be a two-state solution you have to recognise the right of Israel to exist."