The State Department has said more than 40 countries will attended the conference in Warsaw from February 12 to 14.
Palestinian officials have been invited to a USA conference on the Middle East hosted by Poland next week where White House senior adviser Jared Kushner will discuss plans for peace between the Palestinians and Israelis, a senior US official said on Friday.
The peace plan will only be revealed after Israel's April 9 elections, so as not to add difficulties to Prime Minister Benjamin Netanyahu's campaign-seeing as he is already expected to face an indictment before Israeli voters hit the polls.
For the plan to succeed or even pass the starting gate, it will need at least initial buy-in from both Israel and the Palestinians as well as from the Gulf Arab states, which officials say will be asked to substantially bankroll the economic portion.
On Thursday, the Palestinian government branded the event an "American conspiracy".
A foreign ministry statement called the event "an American conspiracy meant to get the participants to adopt the U.S. views on issues of the region, particularly the Palestine question".
The Palestinian Authority has castigated the move, declared the United States no longer an honest broker in negotiations, and rejected any plan the White House may come out with, with PA President Mahmoud Abbas calling it the "slap of the century".
It said it will not follow any points that come out of the conference and it will continue to maintain its current policy condemning the positions of the U.S., which it no longer considers a mediator for peace. Mr Trump has failed to condemn continued Israeli settlement building, has cut all aid to the United Nations agency for Palestinian refugees and reduced funding for Palestinian schools that serve sick Palestinians.
"The economic plan only works if the region supports it", one official told a small group of reporters on Thursday.
Israel has occupied the first two territories since the 1967 Arab-Israeli War and maintains a blockade of the Gaza Strip which has been in place since 2007 after Hamas rose to power in the enclave. Its officials have vigorously denied allegedly leaked accounts of its dimensions, although they have said it will have a detailed economic component aimed at improving Palestinian living conditions.
The Palestinian foreign ministry also criticised Mr Trump for hailing the USA embassy move in his State of the Union address on Tuesday.
"The great stumbling block still ahead in the face of any emergent peace plan is the fact that the Palestinian leadership continues to boycott any Trump administration officials because of Trump's illegal recognition of Jerusalem as the capital of Israel", Hanna said.