WASHINGTON, Sept 13 (Reuters) - Two senior U.S. envoys will return to the Middle East this week in hopes of reviving Israeli-Palestinian peace talks and averting a Palestinian bid to seek U.N. recognition of their statehood, sources familiar with the matter said on Tuesday.

David Hale, the U.S. Mideast peace envoy and Dennis Ross, a senior White House official, will head back for more talks one week after an initial set of meetings with Israeli and Palestinian leaders appeared to make little headway.

The stepped-up U.S. activity comes as President Barack Obama's administration scrambles to head off a Palestinian plan to seek full membership during the U.N. General Assembly session that begins on Sept. 19, despite U.S. and Israeli objections.

U.S. officials fear the Palestinian move could complicate flagging efforts to resume direct peace talks, which broke down last year with the expiration of a 10-month partial Israeli moratorium on Jewish settlement construction on land the Palestinians want for their state.

Israel is lobbying against the Palestinian bid, which it sees as an effort to isolate and delegitimize it and extend the conflict into new arenas such as the International Criminal Court.

The Palestinians are now U.N. observers without voting rights. To become a full member, their bid would have to be approved by the U.N. Security Council, where the United States has said it will veto it.

The United States and Israel argue that issues such as Palestinian statehood should be decided by the two sides at the negotiating table rather than at the United Nations.

Diplomats have said it is not clear what the Palestinians will do when the U.N. General Assembly opens next week.

Rather than seeking full U.N. membership for a state in the West Bank and the Gaza Strip -- territories occupied by Israel in the 1967 Middle East war -- they could seek status as a non-member state, which would require a simple majority of the 193-nation assembly.

The United States, however, said it would not favor this model either.

Our view remains that neither course, neither the Security Council nor the General Assembly, is going to lead to the result that they seek, which is to have a stable, secure state living in peace, that they have to do this through negotiations, State Department spokeswoman Victoria Nuland said on Monday. (Reporting by Arshad Mohammed; writing by Andrew Quinn; Editing by Eric Beech)