* Kerry congratulates "all those elected to office"
* Western states tread delicate course on Kenyatta
* Kenya seen as vital to regional stability
By Richard Lough
NAIROBI, March 9 (Reuters) - Western capitals on Saturday applauded Kenya's peaceful vote but avoided naming president-elect Uhuru Kenyatta, whose election they had said would complicate ties because of the charges of crimes against humanity he faces.
Foreign diplomats in the Kenyan capital, Nairobi, had made it clear in the run-up to the poll that it could not be business as usual when dealing with Kenyatta if he triumphed in the poll, due to his indictment by the International Criminal Court.
"We stand with you at this historic moment and will continue to be a strong friend and ally of the Kenyan people," U.S. Secretary of State John Kerry said in a statement.
While Kerry congratulated "all those elected to office", he did not mention Kenyatta, who won more than half the vote. Kerry's words echoed a statement by President Barack Obama ahead of the March 4 election.
But Kenyatta's supporters may see them as a climbdown from the words of Ambassador Johnnie Carson, Washington's top diplomat to Africa, who before the vote cautioned that "choices have consequences" - seen as a clear hint about America's preferred outcome.
Western powers have a delicate path to tread in their dealings with Kenyatta, who is accused of organising tribal violence in the wake of the disputed 2007 election.
Citing the need for the organisers of the deadly fighting five years ago to be held to account, they are determined that the ICC process be seen through.
But they will be reluctant to jeopardise long-held diplomatic, trade and military ties with Kenya, the lynchpin of east Africa's regional economy and a key ally in the U.S.-led war against militant Islam.
Kenyatta said in his acceptance speech that he and his team would cooperate with all international institutions and that he expected the international community to respect Kenya's sovereignty.
He did not mention the ICC directly, but has previously said that he and his running mate, William Ruto who is also indicted, would cooperate with the court to clear their names.
The real test of Western resolve will come if Kenyatta turns his back on the tribunal, like Sudanese President Omar Hassan al-Bashir.
A spokesman for the ICC, Fadi El-Abdallah, said: "Until now, Kenyatta has been cooperating with the court and we do hope this will continue."
Western diplomats have worked closely on coordinating their stances on Kenyatta. Statements from Brussels, London and Berlin all appeared to follow a similar formula and tiptoed around Kenyatta's name.
Germany said it expected Kenya to uphold its international duties. "This specifically includes cooperation with the International Criminal Court," German Foreign Minister Guido Westerwelle said in a statement.
A statement from Uganda's veteran president, Yoweri Museveni, highlighted the gulf between Western governments and many in Africa, where the ICC is frequently accused of an anti-Africa agenda.
"I am writing to congratulate you on the historic victory you achieved by winning the tightly contested presidential election," Museveni said, adding that the election "had redeemed the honour of Kenya and Africa". (Editing by Edmund Blair and Stephen Powell)