BRUSSELS (Reuters) - U.S. Secretary of State Hillary Clinton said Wednesday she wanted to put on a serious track talks with Russia on a missile defense shield to counter nuclear threats from Iran.

We want to have a more robust and meaningful dialogue with Russia going forward on a range of issues, Clinton told reporters traveling with her to Brussels for meetings with NATO foreign ministers, which will also cover Russia.

Let's put it on a serious track, said Clinton of talks with Russia on a missile defense system that Moscow opposes.

Clinton is set to have her first substantial meeting with Russian Foreign Minister Sergei Lavrov in Geneva Friday when missile defense and strategic arms control are expected to be key topics.

Last month U.S. officials said the United States had offered to slow down deployment of a missile shield in Europe in exchange for Moscow's help in curbing Iran's nuclear ambitions.

Iran poses a threat to Europe and Russia. We think this is a very rich area for exploration and this is what we are going to do, Clinton said.

Just as we had to build a mutual defense with Europe in the 20th century, we have to build it in the 21st century. It is my hope that we will persuade Russia to be part of that defense, she said.

(Reporting by Sue Pleming; editing by Philippa Fletcher)