Updated

World leaders grounded by a shutdown of Europe's airspace were forced to skip the funeral of Poland's president, although some European guests took to the roads to make it in time, AFP reported Saturday.

As airports across Europe remained closed to avoid any risk from a massive cloud of volcanic ash, top guests from U.S. President Barack Obama, German Chancellor Angela Merkel to Britain's Prince Charles and French President Nicolas Sarkozy announced they could not attend Sunday's funeral.

It was not immediately clear Saturday evening whether Russia's President Dmitry Medvedev would also be forced to stay away because of the volcano cloud from Iceland, which spanned Europe Saturday, forcing a no-fly zone over much of the continent.

Dozens of leaders had been expected Sunday in Krakow for the funeral of Lech Kaczynski, killed in an air crash a week ago with his wife and 94 other members of Poland's elite in Smolensk, western Russia.

Obama called acting President Bronislaw Komorowski to express his continued condolences and inform him of his inability to attend.

“Michelle and I continue to have the Polish people in our thoughts and prayers, and will support them in any way I can as they recover from this terrible tragedy," Obama said in a statement.

And Sarkozy’s office said "because of the exceptional weather conditions which are disrupting air traffic over most of Europe the president will not be able to travel to Krakow to attend the funeral of president Kaczynski and his wife, as planned."

EU Commission chief Jose Manuel Barroso canceled his planned trip to Krakow "as he cannot travel by air," his spokeswoman Pia Ahrenkilde Hansen said.

Spain announced Prime Minister Jose Luis Rodriguez Zapatero could not be there and South Korea said it would be represented by its ambassador to Poland.

Sweden's King Carl XVI Gustaf was unable to travel because of the flight restrictions while Foreign Minister Carl Bildt was unable to drive because he would not make it back in time to honor other engagements, officials said.

Turkish President Abdullah Gul and Canadian Prime Minister Stephen Harper also canceled their trips.

Austrian President Heinz Fischer will be represented by his country's ambassador, his spokesman said.

Icelandic President Olafur Ragnar Grimsson could leave his country, home to the volcano spewing the disruptive ash drifting southeastwards into Europe, but would not find an open airport to fly into, a foreign ministry spokeswoman said.

Finland's President Tarja Halonen also pulled out while Norway and Denmark were waiting to see if their political and royal representatives could attend.

Merkel was stranded in Lisbon Friday following her arrival from a visit to the United States. She canceled the trip to Krakow as she was returning to Germany by car from Rome. She was to spend the night in northern Italy.

Leaders of countries closer to Poland resorted to the roads and railways Saturday to be able to pay their last respects to Kaczynski.

Slovenian President Danilo Turk decided to drive, his office said, facing a journey of about 530 miles.

Romanian President Traian Basescu would travel to northwestern Romania by helicopter and then continue by car through Hungary and Slovakia, his office said.

A spokeswoman for Estonian Prime Minister Andrus Ansip said Friday he was ready to make the 800-mile, 18-hour drive to the funeral if air travel remained disrupted.

Czech Republic President Vaclav Klaus, who had tight political ties with fellow conservative nationalist Kaczynski, was planning to make the 326-mile trip by car and train, his spokesman said.

His Slovak counterpart Ivan Gasparovic was meanwhile preparing to drive the 186 miles from his capital Bratislava, while Hungarian President Lazslo Solyom would also go by car from Budapest along with Prime Minister Gordon Bajnai.

Former Ukrainian president Victor Yushchenko left Kiev with his wife at 7am Saturday local time for the long road trip, the press service of his Our Ukraine party reported.

Krakow's airport had said Saturday it was ready to receive up to 40 foreign delegations for the funeral despite the closing of Poland's airspace to commercial flights.

Poland shut its airspace completely Friday to commercial traffic until further notice.

Polish authorities have said that up to 80 foreign delegations were expected to attend the funeral.