UNITED NATIONS, N. Y., May 17—Pakistan asked the United Nations today for food and coastal steamers to distribute relief supplies in East Pakistan.

At the same time, Pakistani authorities disclosed that the Government had invited United Nations experts and foreign specialists to return and resume their work June 1.

Foreign experts left East Pakistan in March when fighting began between Pakistani military forces and supporters of the independence movement in East Pakistan.

The Government's decision to accept assistance was made known here by Muzaffar M. Ahmad, economic adviser to President Agha Mohammad Yahya Khan, after the adviser and other Pakistani officials had met with Secretary General Thant.

The Pakistani President last week replied to Mr. Thant's April 22 offer of aid by saying that food supplies were believed to be adequate and outside help was not needed, but that the situation was being reviewed.

Mr. Ahmad estimated that 30 coastal vessels were needed for relief activity and that requests were being made to a number of governments. Presumably, United Nations assistance was being sought in helping to obtain the needed vessels.